#FabSpace

[zmotorsports]

I'm willing to bet a 6cyl Jeep on 40's isn't towing much.

Just wait 'til he transplants that V8 into it. Then it will do some haulin', haulin' *** that is...

 

[slodat]

I'm willing to bet a 6cyl Jeep on 40's isn't towing much.

He has mentioned that is one of his design considerations. Trying to build a safe rig his son can learn in.

 

[Tyberius]

That's a lot of metal taken out. I guess as long as it's not pulling any heavy trailers or anything it doesn't really matter since it's behind the rear axle?

Seems like there is enough room above and to the rear of the new coil bucket to add gusseting or channel to strengthen the frame rails.

 

[lilscorpion]

Great progress Matt.

I've been away to Ouray for our annual Colorado wheeling trip and had to check in on your progress. Fantastic if I do say so myself.

Thanks! Sounds like you had more fun than we did. We were making great progress until we hit a few project snags and a death in the family which pretty much crippled the project for the last week. We're getting back on the horse today and should be back to full speed ahead as long as we don't run into any more problems...(which we expect to )

 

[lilscorpion]

Wow this is some serious work! I naively had no idea these stretch kits involved this much fab.

It is possible to stretch a TJ or LJ in the rear only without needing to get this involved but you'd only be able to get a couple inches at most. As Mike (ZMotorSports) had commented, a while back, the rear frame side coil buckets create some serious challenges even with just a few inches because of the angle they're installed at from the factory.

In many regards, much of this stretch kit is correcting geometries and bracket locations so that the suspension performs better. Though not absolutely required on a jeep where stretch isn't desired, most of the mods would still be considered a good idea...just most never go there unless somehow they become informed before or during the process of their build as to why they're necessary and/or a good idea.

That's a lot of metal taken out. I guess as long as it's not pulling any heavy trailers or anything it doesn't really matter since it's behind the rear axle?

None of the bracketry removed provides structural support. The two pieces that do are the rear gas tank mount (soon to be removed which will be replaced by a new stronger version) and the cut-out for the new upper coil buckets. I agree with your thoughts specifically in regards to the upper coil buckets though - in cutting a wedge out of the frame will inherently reduct the strength of the frame in that location. The most likely place for failure, during say a towing-like exercise, would be perpendicular to the frame (along the red line) where I'd expect the wedge to "open up" if you will (somewhere within the blue arc). The thicker green line represents the location where the new gas tank crossmember will be installed inside between frame rails this weekend. That crossmember will help a bit but not be the solution.

Seems like there is enough room above and to the rear of the new coil bucket to add gusseting or channel to strengthen the frame rails.

Agreed, thinking something like this maybe. It doesn't need to go edge to edge, it just needs to span the weak spot and tie back into where the frame has it's nominal structure ensuring that the bracket doesn't have ends which are perpendicular to the frame width like in orange. Reinforcements that terminate perpendicular to the frame end up a new weakness fundamentally creating the new failure point. Using scallops (like the pink) reduce that likelihood substantially.

He has mentioned that is one of his design considerations. Trying to build a safe rig his son can learn in.

Agreed. This jeep won't be for workin', long-term (when he starts adulting and I take it back) plans are just to >>>

Just wait 'til he transplants that V8 into it. Then it will do some haulin', haulin' *** that is...

 

[lilscorpion]

Got a call from Lee at Prestine Powder Coating yesterday, our stuff is done. Knowing they’re closed in the weekends, we dropped everything and headed down and pick it up. Turned out to be a nice distraction. When I got there, the sight was…bright! The parts look amazing.



Here’s an up close of the fenders. Lee mentioned that this particular yellow looked like it had shadows in it after a single coat so he applied 2 to make sure it was even. Then, at our request, a clear coat was applied over. Though this is not necessary, experience has taught me that adding the clear results in a near paint-job like finish. The clear adds depth and makes the parts look wet just like it would if you ran multiple coats of clear in a 2 stage paint job.



After getting everything wrapped and loaded, everything was secure for the ride home in the back fo the box truck. Lots of parts.



Andrew couldn’t wait to get some parts on to help visualize the results.



Anytime I make machined parts that someone else is going to finish I always worry that something will turn out wrong. Maybe that I’d not accommodate for the finish thickness correctly. This time I nailed it. Tail light bezels look amazing.



Wife says the dining room now looks like a Jeep shop. I like it.

 

[slodat]

This stage is sooo much fun! Thanks for sharing. Sorry to hear of the loss in the family.

 

[lilscorpion]

This stage is sooo much fun! Thanks for sharing. Sorry to hear of the loss in the family.

Thank you.

It was a lot of fun unwrapping everything with Andrew. Maybe even more fun than Christmas.

 

[zmotorsports]

Matt, sorry to hear of your family's loss.

As for the parts, they look amazing. Very nice contrast with the semi-gloss black and gloss yellow. I'll bet you guys were ecstatic after picking them up.

 

[lilscorpion]

Last step in prepping for the rear differential is to remove the rear gas tank and prep for relocating it 5” rearward. First, gotta get it out.

The factory LJ gas, fuel pump, and sender all work so we’ll keep it. In it’s current location there isn’t enough room for the Dana 35 which had the punisher diff cover guard on it. You can see the rust spot half way up in the middle, it’s from that punisher logo coming in contact with it during (the limited) suspension cycling.



The tank is removed easily. There’s a
breather hose, fuel pressure, and return line that need to be disconnected. The fill neck can come out without removal if you navigate it around the frame on the way down. The electrical connector releases easily (once you figure out how the dang thing releases, I never can remember).



The tank is suspended from a cross member that spans the two frame rails immediately behind the diff. The holes are where the body mounts attach the frame to the body



Stacking the two crossmember on top of each other and aligning the body mount holes you can see how much the gas tank gets shifted rearward. It’s enough to accommodate a larger axle (in our case a Dana 60) and shift the axle rearward that ~4-inches.



Jeep made it easy for those who want to move back their tank and make extra room. Jeep installed 2 rear cross-members and, as luck would hav it, they’re the same as each other - same shape, holes, form, size, etc. Since they’re the same, all you have to do is remove the gas tank mounting bolts and move them back to the other cross-member (the Jeep TJ in this year used the rear cross member so now it’s fundamentally the same as the TJ).



That picture wasn’t the best. Here’s a better angle that shows the similarities and simplicity of the mod. Remember the front gas tank crossmember picture above where we showed the difference in location between the new crossmember and the original? The difference shown below is the same difference...makes sense.



Back to the cut off wheel and sawzall. Pictures make it look so easy.



With the x-member on the bench, the four bolts are removed by removing the push on lock washers.



You can spend a bunch of time trying to re-use them but in my experience, it’s best to just cut them and replace them with new ones.
These are really just shallow head carriage bolts.



I’ve been replacing most of the hardware we’ve taken off but these only have light surface rust so we’ll clean ‘em, paint ‘em, and run ‘em. After hitting them with the wire wheel, they’re like new.



And with fresh coat of paint they should be good for the next dozen years. These bolts are 5/16-18 which makes them slightly smaller diameter (.305ish) than a course thread 5/16 bolt (.315ish). I could not find new push in locking washers designed for .305ish bolts so I had to purchase the larger size and figure out how to make them work. The way I did was to smack them once or twice with a body hammer to flatten out the tabs so they’d work on smaller bolts. All the have to do is retain the bolt in the rear cross-member. With these, the tank is ready to go back in.



Time to shift back to the belly pan but before I do, d since some of you have commented on how much metal I’ve removed from the back of this Jeep, let’s take a final inventory of the parts I’ve had to cut out of the LJ’s to move the rear axle back. From top to bottom: 2nd rear cross member, Front gas tank and rear upper shock mount cross-member, upper rear sway-bar mounts, rear upper coil buckets (and frame wedges), rear upper and lower control arm mounts. Yeah, everything in the rear that was attached to the frame except the rear-most crossmember.

 

[lilscorpion]

I have to get that tape off of the Jeep (according to Andrew)..



The good stuff ain’t cheap but does come off easily.



I’m with him, it looks much better. I think he was tired of showing his friends pictures around the blue tape.

 

[ClappedOutBport]

5/16-18 is the coarse thread btw. Bolts must have just been undersized.

I have to get that tape off of the Jeep (according to Andrew)..


The good stuff ain’t cheap but does come off easily.



I’m with him, it looks much better. I think he was tired of showing his friends pictures around the blue tape.

When I replaced the top on my BMW Z3 I taped up the hole with frog tape for protection and I wish I didn't. I pulled off a bunch of clear coat, and now it's falling off the whole quarter panel. A couple of little dings would have been NBD. I'm super weary of every putting tape on a car now.

Mods are looking great, thanks for all the detail you put into the thread.

 

[lilscorpion]

5/16-18 is the coarse thread btw. Bolts must have just been undersized.







When I replaced the top on my BMW Z3 I taped up the hole with frog tape for protection and I wish I didn't. I pulled off a bunch of clear coat, and now it's falling off the whole quarter panel. A couple of little dings would have been NBD. I'm super weary of every putting tape on a car now.



Mods are looking great, thanks for all the detail you put into the thread.

Duh, you’re right, 5/16-24 is fine. Now I have to go back and look at them. Maybe my problem isn’t one. Thanks!

 

[zmotorsports]

Looking great Matt, although the blue painter's tape did give it some character.

 

[lilscorpion]

Wrapping up the final steps of the rear gas tank relocation kit. Got the crossmember installed using the two body mounts. It will be welded to each frame rail on either side once I get the rear diff in.



Here’s a birds eye view of the gas tank now that it’s out which shows the two flanges that suspend it from the rear crossmember and the new gas tank crossmember. Saving things like this for Andrew to have for future reference. Thought I’d share.



Got the bolts reinstalled in the rear crossmember.



A previous owner must have thought that towing something with an Jeep is a good idea so he installed a trailer light plug (silly). So you guys are clear on the intentions for this Jeep, I cut all of it out.



The intention is to drop the tank into this new skid plate made by GenRight which is designed specifically for the factory tank. It’s a powder coated 3/16-inch steel unit that yields 1” ground clearance gain over stock. The damn thing is heavy. I think it will leave enough room for the Dana 60 but aren’t completely sure yet.



Andrew removed the sticker that GenRight put on it. When I asked him why, he said “they didn’t pay us for advertising.” That’s my boy.

Ok, on to the rear diff prep.

 

[lilscorpion]

I’m so excited to get the rear diff in the LJ. With it just coming out of the crate, I now have a significant portion of my shop back. Almost all of the boxes are empty and ready for the trash guy on Monday. After they’re gone, we might even be able to get two cars in the garage again.



When we ordered it the 60’s from DynaTrac, we had a slightly (read completely) different plan for the Jeep. We were thinking about running mid-length arms (like off of a JK) and a conventional front and rear 4-links with trac-bars. It is for that reason why this differential has the brackets that it does and, sadly, our plans have changed so much that they all need to now be removed.



Upper control arms will be removed and replaced with an axle truss which has upper integrated triangulated control arm mounts. Coil buckets will be replaced with buckets which enable 1.5” coil spring offset (reminder - the other 2 1/2” of stretch was handled by the upper coil buckets I cut in a few posts ago.



Upper control arms were easy since I had asked for them to only be tac-welded on just in case. The truss was semi-in the plan from the beginning.



Coil buckets weren’t nearly as easy. They had been burned home well. Fortunately 39 minutes with a cutoff wheel and a little bang bang if the impact hammer and they came right off.



Mocking up the rear truss. Looks good but as I tried to place the coil buckets on, I found that the truss wasn’t centered on the differential.



The center section was 1/2” biased to the left and about 2” too wide overall.



Too long is easy to solve. I carefully marked what needed to be removed and went to work with the cutoff wheel. I started with the top of the truss.



And then cut both sides. This allowed me to use the top groove as a guide on most of the cut.



I also needed to cut in a few reliefs to clear part of the housings casting profile.



After about an hour, the truss now was symmetrical and the right length.



I was shipped a set of small tube offset coil buckets. Quick trick - when converting from small tube to big tube, all ya gotta do is lay the marker length-wise on the tube and mark.



Should look something like this.



Grind away the waste.



And Bob’s your uncle.

And check the fitment next to the truss. Ready to install.



With the fab work done to the truss, we just need to get a little paint on it and it’s ready to go in. We always use self etching primer as a base on all out parts. T may not be totally necessary but it does help reduce rust over time.



With a few good coats I then use some scotchbright to make sure the surface is smooth.



Andrew then took the parts into his “paint booth” to give them color. When it’s a little windy we use this area because the combo of houses and fences eliminate wind. It’s dead calm always.



I scuffed the truss edge so it’s ready to be welded on. This picture was funny, I kept telling him to move and hold it higher...all just to see how long I could get him to hold it. It’s heavy.



We’re still hopeful that we’ll be able to use the brackets Dynatrac installed for the lower control arm mounts and the lower shock mounts. We’ll be able to verify, and finalize all of the other bracket location (angles and whatnot) once we get it under the vehicle. Once we lifted it off the jack stands, Andrew scooted it over to the jeep.



With the diff in place we made a little make shift plumb bob out of a countersink and some heavy duty thread I stole out of my wife’s sewing box. We attached the plumb centered in the wheel well. We’ll want the tire to land in absolute center at full compression so we can take advantage of the entire wheel well (and full travel). This presents us with some setup challenges. We’ll need to cycle the suspension through all 3 cycles: (1) Full stuff passenger w/ drivers drooped out, (2) Full stuff driver’s with passenger’s drooped out, and (3) Full stuff both sides. There’s a really good chance that we won’t be able to accomplish absolute center on all 3 conditions so we’ll favor the rock crawling conditions (full stuff drivers and passengers independently) since this jeep should never take to the air.



Once we had it centered in the opening, lined up the new coil buckets. Quickly we realized that they weren’t going to work. The least amount of offset was too much by more than an inch. We’ll have to go back to the factory buckets (*****, just cut them off).



Under the vehicle we learned that at full compression, we’ll need to run at least 4” bumpstops which isn’t really crazy, that’s what we need up front. Shock mounts don’t align well and the lower control arm brackets are totally wrong. All will need to be removed.



I spent the next half hour taking measurements trying to figure out where I went wrong. The rear upper brackets were supposed to yield a 2.5” shift to the rear and these lower buckets were supposed to get the other 1.5”. Based on my measurements, I somehow got all 4” of rear stretch just from the upper coil buckets. The means I didn’t need to cut off the other buckets...and now I’ll get towels them back on.

Andrew has been wanting to weld really badly but I have not let him this far since the only thing we’ve had to weld on has been a vehicle which seems like a really bad place to learn. That being said, he finally figured out how I’d let him weld - if he just dies the tac-welds. So I let him, and he did great.



He did about 3 out of positions welds too. Builds character I say.



Pulled the truss back out of the vehicle and cut off the lower control arm mounts and the shock mounts, and did a final fit on the truss.



Reviewing the changes that were necessary to get the truss to fit correctly. In hindsight, there were a few mistakes made on the rear differential. First, the design of the truss was dependent on specific build measurements of the housing. To make it work, I had to remove 2 1/8” off the passengers side and 1 1/2” off the drivers.



Second, there were assumptions that my build was going to be the same as the build the stretch kit was designed on/for without really knowing all details. My diffs had larger diameter tubes, my diff had a few housing casting features the other must not have had, and my diff didn’t end up needing the off-set coil buckets. Andrew have talked about this more than a few times now. He’s getting a little frustrated that we can’t just install the parts and that almost everything has required some amount of fabrication to make it work. He’s learning that those elements that make a project custom, is where the work also tends to be.



Final step before the diff can go back in the vehicle is to tac-weld on the lower control arm mounts, the truss, and the buckets. If all goes well, it’s done done and we can now get the jeep back under all 4 feet again. I did a once-over to make sure that the parts are tac-welded on well enough to support the vehicle weight and the cycling of the suspension. Meh, should work.

 

[Arclitgold]

Looking fantastic!! Can’t wait to see this puppy back together


Sent from my iPhone using Tapatalk

 

[zmotorsports]

Lookin' good Matt.

 

[lilscorpion]

Looking fantastic!! Can’t wait to see this puppy back together

Lookin' good Matt.

Thanks guys! Only a matter of days and we'll have it on all 4's again. Can't wait.

 

[zmotorsports]

Thanks guys! Only a matter of days and we'll have it on all 4's again. Can't wait.

That is a big milestone on a project like this. I remember about a year ago when we were doing the suspension on my son's WJ that I kept thinking getting it sitting on all 4's will at least make me feel like we're making progress.

 

[gearhead1960]

Thanks guys! Only a matter of days and we'll have it on all 4's again. Can't wait.

Matt,

What a great learning and hair growing experience for your son. He will come to appreciate the time and effort for this build when he experiences the capabilities you've built into this (soon to be) beast!

Even though I am not a Jeep enthusiast, I can appreciate the craftsmanship and skill it's taking to do the build. My hat is off to you and your son.

 

[lilscorpion]

Matt,



What a great learning and hair growing experience for your son. He will come to appreciate the time and effort for this build when he experiences the capabilities you've built into this (soon to be) beast!

Thank you for the compliments, they’re much appreciated.

I hope it’s hair growing (literally). I’m balding and his mother’s father is very bald. He has like no chance.

That is a big milestone on a project like this. I remember about a year ago when we were doing the suspension on my son's WJ that I kept thinking getting it sitting on all 4's will at least make me feel like we're making progress.

I hear you. I think complicated builds tend to have 80% if the build only visually look like 20% of the progress. Then, in that last 20%, you’re wrapping up with the easier but big ticket items which look like big visual progress. Like when you got all of the WJ parts back from Powder. Beginning of the day the Jeep looked totally torn apart, half a day later, it looks done. I wish Andrew saw it that way though. He’s starting to get a little frustrated at the lack of progress...hopefully that will subside this weekend when we put in all of the coated parts. [emoji857]

 

[lilscorpion]

Last prep step for the rear differential is the rear belly pan. This unit is a complete cross member that attaches to the frame and the rear of each of the side plates I previously installed…and it’s freakin’ heavy. Probably half again as heavy as both of the side plates (previously installed) put together.



There’s good reason for it’s weight. There’s a bunch of **** going on within this part. Chassis side arm location and separation are handled through carefully placed control arm mounts which fit nicely up under a tub with a 1” lift. I think it may also fit without…though it would be damn tight. The rear of the crossmember has attachment points which will, when installed, interconnect the side plates and the skid (which I’ll be installing at a later time).



Installing it in the jeep, other than having to lift it, is fairly easy. The rear two factory skid plate holes are reused as the front two on the crossmember. Andrew had to work I I tried to tackle it myself. When laying on the ground the vehicle was just low enough that I could roll under my jeep on the creeper, crossmember on my chest, two bolts in my mouth, and bench press up the crossmember up into place. I then was able to support it with a knee and a forearm while inserting the bolts into the existing bungs one at a time.



With the belly pan now suspended from the frame, I was then able to reposition the jack to support it from below while I marked where I needed to drill into the frame.



After center punching, I use a small drill bit to pre-drill the hole. Smaller drill bits wander less and, as a result, the holes end up perfectly centered. Though the magic of the internet could make it seem like I took the crossmember out myself, I actually had to wait a few hours for Andrew to get home and help me. Though I tried, removing the pan by myself ended up being a lot more scary/hard than installing it seemed to be.



These threaded weld-in bungs are included in the kit. They have a shoulder similar to the shoulder of the factory inserts which is beefy enough to burn home hot.



The smaller dimension on the weld-in bung is 1/2” and a step bit makes quick work of getting the size right.



I ordered a welding jacket specifically for this weld. Though I weld just fine laying on my back, it seems that my worst burns have always happen when doing something like this.



The rear crossmember is the re-installed and ready for the upper and lower rear arms. This picture makes it a little easier to visualize just how much under belly protection this suspension system provides. When we get to it, the entire center section (between the side plates) will get a 1/4” steel skid which also tie the side plates into the rear cross-member.



So close now, time for the rear diff.

 

[lilscorpion]

To get the rear diff installed I need to setup the rear control arms. With the differential mocked up where I think it will need to be, I was able to pull a rough measurement for the initial control arm setting lengths. Starting point for the lowers is 35 1/2” center to center.

The lowers are beefy units. 2” x .250 DOM tubing with Summit Machine flex joints to handle the mis-alignment.



The adjustable end also utilizes a Summit Machine flex joint and a massive 1 3/8-inch threaded assembly with ~ 2 1/2” of adjustment while still having a full 1 1/2” of thread engagement. That should be plenty of wiggle room to dial it in to our application.



Well 2 1/2” wiggle room should be enough but I wasn’t so sure. While trying to figure out where I was going to land for arm length, there was enough variability in the parts mix-and-match that I ended up with uncertainty of almost 3” in length. To make sure I had what I need when things finally came together, TNT sent me an additional set of flex joints which they use in situations where the arms need to be a bit longer. The short are ~5” in length and the longer ones are ~7” in length so now we have almost 5 total inches of wiggle room. That should be more than enough to get where we need to be regardless of how things go together.



After assembling both lowers with a little bit of anti-seize, we got them mocked up in the rear-end by attaching them to the lowers that were previously tac-welded to the housing.



And into the lower control arm mount location frenched into the rear cross-member on the frame-side.



With the two installed, we’re able to set the pinion angle temporarily enough to pull a tape and get some initial measurements for the upper control arms.



Same boat on the upper arms.



Sometimes the threaded assemblies can be welded into the arm in different phases (in relationship to the spherical ends) which can make adjusting them to the same measurement difficult. Since the flex joint assemblies have grease zerks on only one side and only can be installed upwards in the brackets, it’s possible for the threads to be out of phase enough to make it impossible to get them within 1/12th if the same length. In this case, we were able to get them exact enough that I could bolt the pair to each other which was awesome.



With all of the arms in, we cycled the suspension and check where the bumpstops hit, ensure the axle is centered, and running perpendicular to the chassis so it doesn’t cat walk.



Cycling the suspension is much easier on a 4-link setup. Without a trac-bar messin’ up the works, you can just balance the center on the jack and tip it side to side. With basic measurements I’m able to verify that the 40” tires will just barely fall short of the fenders at full stuff which is perfect.



After cycling the suspension, it was time to play with the coils to see which pair we wanted to use. We had 2 - one was what we pulled out of the vehicle before we cut it apart (old man EMU) springs approximately 2 1/2” lift over stock (which are broken in), and a set that TNT sent me which I was told were about 4 1/2” of lift over stock (brand new, need break-in).



Though we like the idea of a monster truck (Andrew more so than I), we also didn’t want any more lift than we absolutely had to have mostly due to the performance advantages a short 4x4 has over a tall one on rock face and obstacle climbs. We tested both and found that the shorter springs yielded ~8” of wheel well visible in the rear and the taller ones yielded an 11” wheel well. Since the OME springs were already broken in and the TNT ones clearly weren’t yet, I was fairly confident that the TNT springs would likely yield about 2” more lift once they had. For that reason, we decided to start with the old/original OME springs as a baseline and we found 9” of travel.



Once it came off the jack stands, I knew almost immediately that the height is exactly what I was hoping for. Low center of gravity and tough-looking on 40’s



Probably the coolest is the ground clearance. 40’s and high-clearance axles are a sweet combo. This rig has just shy of 13” of ground clearance at the low-point on the housing.



And 17 1/2” under each of the differential tubes.



That’s a significant advantage in the rocks. I installed the new gas-tank crossmember to see how much clearance I’d have at the face of the diff and above the upper control arm mounts. Twisted up I determined that I needed a 4” bumpstop to prevent the tire from getting into the fender (with about 1” clearance). The clearance at the center of the tub is exactly 5”…which matches the 4” of travel we already calculated at each wheel.



It appears that the diff cover will just barely miss the gas tank. I’ll have to get it in before I’ll know if it will or not. Up next, gas tank.

 

[slodat]

I'm not a 4x4 guy and I don't know much about them. This build makes me want to build one someday! I am blown away by the whole thing!! Bad ***!

 

[lilscorpion]

I'm not a 4x4 guy and I don't know much about them. This build makes me want to build one someday! I am blown away by the whole thing!! Bad ***!

Thank you. We’ve gotten to the point where we can see it now and are getting really excited...yet we have so many things left to do it feels like we have so far left to go. I think it’ll become real right about the time all of the body panels, bumpers and sliders are re-installed. We’re thinking maybe this coming weekend!!

Edit: you should build one.

 

[Bigblue&Goldie]

Nice write up as always! I really like how the lower links french into the skid plate on the chassis end. You don't hear about TNT much, but their products look really well made.

 

[zmotorsports]

Lookin' good Matt.

I was surprised with my little ProRock44 front housing that I have 12" of clearance sitting on 37's and about 11.25" in the rear using the OEM Dana44 housing. The difference being that 60 of yours is beeeeeefy and much bigger than my little 44.

She's turning our great, can't wait to see it on the trail.

On a side note, I just ordered a heavy duty set of rear coils for mine so I can dial it in just a tad bit closer to where I want. I have a set of Currie 4.5" overland coils under it now and still had to add a 1" Teraflex spacer to get even close to where I want to be. I ordered a set of Metalcloack heavy duty coils that should give me a little more height and stiffer spring rate to carry the heavy *** of my Jeep around so I'm anxious to get them in and try them out as I would like to have all coils under there and not rely on that spacer to get me my ride height. Also I want the rear about .5"-.75" higher if I can as it is squatting just a little bit more than I want.

 

[lilscorpion]

Nice write up as always! I really like how the lower links french into the skid plate on the chassis end. You don't hear about TNT much, but their products look really well made.

As I understand it, TNT’s goals aren’t to operate at scale (produce, advertise, distribute) and instead to stay small so they can focus on custom work. That may be why their name isn’t as known as Poison Spyder Customs. They do typically production-ize most of their custom parts over time and make them available via their parts catalog and through their vendor network to those who want custom. They do have a following.

[QUOTE =zmotorsports;8061212]Lookin' good Matt.

I was surprised with my little ProRock44 front housing that I have 12" of clearance sitting on 37's and about 11.25" in the rear using the OEM Dana44 housing. The difference being that 60 of yours is beeeeeefy and much bigger than my little 44.
[/QUOTE]

Thanks! The ProRock chunks do have more clearance than the standard chunks and it’s impressive that they can provide as much more as they do. Though not obvious by the picture, the rear we chose is a standard Dynatrac chunk (not a ProRock) because we didn’t want a reverse rotation in the rear. Though many do use the PR in the rear, and Dynatrac does state they have a special slinger to help in oiling the pinion bearing, I learned that the special slinger is just them making a little modification to a normal slinger. Without understanding how accurate/repeatable/successful this modification is, it’s difficult to want to allow it in a near $10k axle that only has a 1 year limited warranty. If they were to give me a lifetime (or more reasonably maybe 5 year) pinion bearing warranty, maybe.

[QUOTE =zmotorsports;8061212]

She's turning our great, can't wait to see it on the trail.

On a side note, I just ordered a heavy duty set of rear coils for mine so I can dial it in just a tad bit closer to where I want. I have a set of Currie 4.5" overland coils under it now and still had to add a 1" Teraflex spacer to get even close to where I want to be. I ordered a set of Metalcloack heavy duty coils that should give me a little more height and stiffer spring rate to carry the heavy *** of my Jeep around so I'm anxious to get them in and try them out as I would like to have all coils under there and not rely on that spacer to get me my ride height. Also I want the rear about .5"-.75" higher if I can as it is squatting just a little bit more than I want.[/QUOTE]


I wanna see it on the trail too! If we get it done in time for your next Co run, maybe we’ll meet ya and run one together.

In regards to JK coils - would appreciate your feedback once you get those TF coils in there. I’ve tried OME and now AEV and right now like the AEV best. I can’t speak to rose height and consistency because I’m running JKS ACOS front and rear which allows me to keep the Jeep level no matter what. I like you prefer the rear to be a smidge higher. Maybe look into them if rode higher tuning is your main goal. Springs inherently change over time making leveling via poly coil spacer very difficult and sometimes frustrating.

 

[zmotorsports]

That's where I'm at now Matt. Just trying to dial in that last little bit of ride height now that I have it equipped and loaded the way it will be for the foreseeable future. I prefer the front end rides just a little higher than the rear but mine is a little lower in the rear than I like after adding my dual Powertanks and a few more pieces to my recovery bag. If I could get the rear about .5" to may .75" higher it would still be just a little lower in the rear than the front and in my opinion be about perfect. I'm not going all out on the low center of gravity for my Jeep because I don't want to get into cutting up the body but I do want to keep my suspension travel and not limit the hell out of it just to run 37's and keep it low. I still need some lift to get over the rocks/obstacles due to these buses (Jeep JKU's) having such a low breakover angle but I am trying to keep it around that 4 inch range and at least keep that belly high enough to get over most of the obstacles on the trails that I run. I currently have 4.5" linear rate BDS coils in the front with the ACOS spacers at nearly the lowest setting which is netting me right about 4.25" overall lift over stock and still around 4.25" of uptravel and 5.75" of droop for a 42/58 uptravel/downtravel percentage.

With my 4.5" Currie overland rear coils and a 1" spacer I am in the 3.5" range due to the weight of my Jeep. The Metalcloak dual rate springs I just ordered have about 1.5" longer free length and a little stiffer rate so I am hoping that is the magic number to get me right to that 4" lift height in the rear without having to remove any of my "stuff".

It's funny as I have pretty much given up on the "keeping the Jeep light" thing as I carry so many tools, fluids, gear, etc. that there is no way to keep it light. I know they wheel better being light but I just can't go out on the trail without all of my tools and gear without worrying as I hate relying on others. I need to be self reliant on the trail. What bothers me though is some of our club members don't carry anything other than a cooler and maybe a couple of lawn chairs because when they have issues they know there are plenty of people who carry all of the tools necessary so they don't need to. A lighter Jeep would get over the obstacles easier and down the trail better but I guess that's why I had to add HP to the equation.

 

[lilscorpion]

I'm not going all out on the low center of gravity for my Jeep because I don't want to get into cutting up the body but I do want to keep my suspension travel and not limit the hell out of it just to run 37's and keep it low. I still need some lift to get over the rocks/obstacles due to these buses (Jeep JKU's) having such a low breakover angle but I am trying to keep it around that 4 inch range and at least keep that belly high enough to get over most of the obstacles on the trails that I run. I currently have 4.5" linear rate BDS coils in the front with the ACOS spacers at nearly the lowest setting which is netting me right about 4.25" overall lift over stock and still around 4.25" of uptravel and 5.75" of droop for a 42/58 uptravel/downtravel percentage.

That’s right about where I am but running more acos and less coil. Have been thinking about flipping that and going to a taller coil. Honestly, I’m not sure it will make much of a difference either way.

What shocks are you running?

With my 4.5" Currie overland rear coils and a 1" spacer I am in the 3.5" range due to the weight of my Jeep. The Metalcloak dual rate springs I just ordered have about 1.5" longer free length and a little stiffer rate so I am hoping that is the magic number to get me right to that 4" lift height in the rear without having to remove any of my "stuff".

Are you thinking there’s a benefit of the longer free rate or is it all about the final/net lift height on this swap?

It's funny as I have pretty much given up on the "keeping the Jeep light" thing as I carry so many tools, fluids, gear, etc. that there is no way to keep it light.... A lighter Jeep would get over the obstacles easier and down the trail better but I guess that's why I had to add HP to the equation.

If weight was a concern, neither of us would be driving a JK, we’d have LJ’s. [emoji41]

It’s easy to pack and carry too much stuff but “too much” is subjective. For a while I carried everything I thought I might need. To your point through, because I came prepared (tools and a correctly equipped and configured vehicle), I rarely used my tools on my rig, but almost always on other’s rigs who didn’t come adequately prepared (tools or configured vehicle). If I had a welder and a 4 1/2” grinder, I’d find myself doing a 3 hour trail repair on a vehicle that’s not even running with my group and most likely had no business on that particular trail. When I had the business it made sense because it served as a means to advertise, but now it doesn’t...so I’ve started to pack only what I need based on how I’m equipped...but light(er) now for sure than before.

Adding HP makes everything better junk in the trunk or not.

 

[zmotorsports]

That’s right about where I am but running more acos and less coil. Have been thinking about flipping that and going to a taller coil. Honestly, I’m not sure it will make much of a difference either way.

What shocks are you running? I am currently running Fox 2.0 shocks and really like the way they are valved right out of the box. I've had Bilstein as well as BDS on it and I would take the Fox's over either of them for a daily driver/weekend wheeler. They seem to be a nice balance of compression and rebound yet still the travel I sought.

I just can't bring myself to go the coil over direction because in my opinion they have just as many cons as they do pros. With coil over's being all the rage lately it still befuddles me that many Jeep owners don't know why they have them other than the "cool" factor". If you need the actual wheel travel then yes, the coil overs are hard to beat when you get past that 12 inch travel range. However, if you are in the 8 to roughly 11 inch range of travel and you have the proper coil spring and shock there really is no advantage of a coil over. Actually more disadvantage in my mind because of initial cost and then the annual maintenance and don't even get me started on the squeaks/noises. Also I don't feel that overall suspension travel is end all/be all of what makes a car perform off-road. To some the whole suspension travel thing is just how high you can climb an RTI ramp or how far you can droop out the front axle but if you can't convert that to traction and climbing up an obstacle it is all for not and you can only have so much uptravel for a given application. I've seen people droop out so far that the front tire routinely gets caught under a ledge and can't climb up and over vs. a car right behind them with smaller lift and limited grab the edge of the rock and climb right up and over.



Are you thinking there’s a benefit of the longer free rate or is it all about the final/net lift height on this swap? I do want another .5"-.75" of lift in the rear end of my Jeep, however, I am leaning more towards the benefit of additional spring rate moreso than just the free length, although the free length is about 1.5" more on these new ones that I just ordered.

I have a theory, and it is just a theory at this point. During my initial trip to Moab in April I wasn't able to fully test my theory because I had a major interference in the front with my bumper and a minor interference in the rear with my inner fender but now that I have them corrected I've been playing with bumpstop and now spring rate to prove/disprove my theory. I have taken notice over the past couple of times off-road that when I am climbing a fairly steep grade and the weight shifts to the rear of my Jeep that I may be compressing a bit more than I should and therefore possibly unloading the front end a bit and losing some traction. My thinking is that by adding some additional resistance to compression in the rear (added spring rate) that the rear will compress less on these steep obstacles and therefore help to keep the rear off of the bumpstops and keep the front end planted more firmly resulting in better traction at the front tires. I had added the spacers to the rear and really didn't notice any difference other than a little bit of raised height in the rear so this has directed me to look more at spring rate vs. merely overall length of the coil spring.

I am concerned about two things. One possible negative aspect of having a stiffer spring rate in the rear having the opposite affect on descending these steep obstacles and having the rear unload easier due to the weight shift and higher spring rate lifting the rear. The second concern is overall ride comfort on the pavement as right now it rides fantastic and I don't want to sacrifice that with a harsh ride.

Again, this will require some testing once I get the springs installed but I've been "mulling" this over in my head for the past few trips now and finally feel I have a good enough seat of the pants feel that I can replace the springs and give my theory a try.




If weight was a concern, neither of us would be driving a JK, we’d have LJ’s. [emoji41]

It’s easy to pack and carry too much stuff but “too much” is subjective. For a while I carried everything I thought I might need. To your point through, because I came prepared (tools and a correctly equipped and configured vehicle), I rarely used my tools on my rig, but almost always on other’s rigs who didn’t come adequately prepared (tools or configured vehicle). If I had a welder and a 4 1/2” grinder, I’d find myself doing a 3 hour trail repair on a vehicle that’s not even running with my group and most likely had no business on that particular trail. When I had the business it made sense because it served as a means to advertise, but now it doesn’t...so I’ve started to pack only what I need based on how I’m equipped...but light(er) now for sure than before.

I agree 110% with ya Matt. Similar to when I was racing, I would bring my welder and all other tools with me to the track and end up working on everyone else's stuff that brought theirs to the track knowing I would have the necessary tools and equipment. In my Jeep I carry the tools that I think I might need and try to keep it maintained that I don't need to use them on mine but have them "just in case". Like you, I have used my tools more on other people's Jeeps on the trails but that's ok because at least we're able to get them off the trail and not leave them behind. I don't carry welder or anything of that sort in my Jeep but have assisted on a few trail repairs of others that have had them and would just as soon try to prevent that kind of failure on the trail because trail repairs never turn out ideal and always need to be cut back apart or just replaced once off the trail.

Adding HP makes everything better junk in the trunk or not.

Hope all of that makes sense and I would appreciate your thoughts Matt as you've probably played with or toyed with the same thoughts as I at one time or another.

 

[lilscorpion]

I am currently running Fox 2.0 shocks and really like the way they are valved right out of the box. I've had Bilstein as well as BDS on it and I would take the Fox's over either of them for a daily driver/weekend wheeler. They seem to be a nice balance of compression and rebound yet still the travel I sought.

Agreed completely on the fox shocks observation - out of the box the balance I’d rebound an compression is a good mix. The Bilstein shocks have a dis-proportionate rebound to compression ratio heavily favoring the rebound even though they share the same category as the Fox 2.0 - listed as mono-tube gas charged. According to the specs, the fox shocks are factory set to roughly 300psi whereas the Bilstein shocks are less at 200psi. Irrational as it may seem, the fox actually seem soother all likely due to the valving differences. Right now I'm running the Bilstein's and about to switch back to Fox. Think you're in a good spot personally, wouldn't change a thing.

I just can't bring myself to go the coil over direction because in my opinion they have just as many cons as they do pros. With coil over's being all the rage lately it still befuddles me that many Jeep owners don't know why they have them other than the "cool" factor". If you need the actual wheel travel then yes, the coil overs are hard to beat when you get past that 12 inch travel range. However, if you are in the 8 to roughly 11 inch range of travel and you have the proper coil spring and shock there really is no advantage of a coil over. Actually more disadvantage in my mind because of initial cost and then the annual maintenance and don't even get me started on the squeaks/noises. Also I don't feel that overall suspension travel is end all/be all of what makes a car perform off-road. To some the whole suspension travel thing is just how high you can climb an RTI ramp or how far you can droop out the front axle but if you can't convert that to traction and climbing up an obstacle it is all for not and you can only have so much uptravel for a given application. I've seen people droop out so far that the front tire routinely gets caught under a ledge and can't climb up and over vs. a car right behind them with smaller lift and limited grab the edge of the rock and climb right up and over.

primary (and two biggest) differences between coils and coil-overs is that the coils ride on the shock body which enables the design/configuration of the coil to be altered by how it's mounted. e.g. - tipping the coil-over assembly to a 30* angle defeats/reduces the deigned spring rate of the coil itself. As a result, we can take a 250lb coil and, by changing the mounting angle of the shock, dial it in to a more exact force up to 250lbs. A conventional coil doesn't allow that, it must run near perpendicular to the ground or it could be damaged. We have even more tuning options given that most offer dual coil setup which gives us the ability to have primary and secondary coil rates as well as adjustment to when the primary transitions into secondary. Valving and maintenance on the coil-overs vs. non is a isn't really any different assuming you're comparing the same class of shock - both will require the same amount of maintenance.

I don't really want coil overs because I've never bothered to learn how to valve and rebuild them even though I've had them on 2 vehicles now (quite a long time ago). If/when I do actually learn, I'll probably only run them again. I hate coils. Hate the way they mount and how difficult it is to get them to sit where I want them and with the desired spring rate. As luck would have it, right now Andrew and I are fighting to get the LJ to work predictably with the coils. We have 3 sets now and the closest we can get is with the OME 2 1/2" coils and spacers. It feels like such a waste of time.

I have a theory, and it is just a theory at this point. During my initial trip to Moab in April I wasn't able to fully test my theory because I had a major interference in the front with my bumper and a minor interference in the rear with my inner fender but now that I have them corrected I've been playing with bumpstop and now spring rate to prove/disprove my theory. I have taken notice over the past couple of times off-road that when I am climbing a fairly steep grade and the weight shifts to the rear of my Jeep that I may be compressing a bit more than I should and therefore possibly unloading the front end a bit and losing some traction. My thinking is that by adding some additional resistance to compression in the rear (added spring rate) that the rear will compress less on these steep obstacles and therefore help to keep the rear off of the bumpstops and keep the front end planted more firmly resulting in better traction at the front tires. I had added the spacers to the rear and really didn't notice any difference other than a little bit of raised height in the rear so this has directed me to look more at spring rate vs. merely overall length of the coil spring.

Weight transfer from front to rear isn't the greatest when attempting a climb. Stiffening up the springs may help but I'm not sure it will overcome acceleration and inertia...especially when your go pedal is attached to a 450hp. Unfortunately Physics isn't my strong suit so I can't back it up with data. Theoretically I'd agree with you so I'm super interested in what you find once you get a chance to test your theory.

I am concerned about two things. One possible negative aspect of having a stiffer spring rate in the rear having the opposite affect on descending these steep obstacles and having the rear unload easier due to the weight shift and higher spring rate lifting the rear. The second concern is overall ride comfort on the pavement as right now it rides fantastic and I don't want to sacrifice that with a harsh ride.

What I'm thinking as well. We spend so little time on more extreme climbs that the cons may overwhelm the pros of running stiffer springs. Some race rigs run a small-duty winch in the front and **** down the front end as they go into the climb which I think counter-acts much of the above and weight transfer as well. I'll be curious to hear how your tests go.

Like you, I have used my tools more on other people's Jeeps on the trails but that's ok because at least we're able to get them off the trail and not leave them behind.

Last 2 opportunities to help someone I ended up helping them to food/phone/safety and they went back to get the vehicle with real help. Now that I'm getting to the ages of wisdom I'm starting to be weary of the trail repair that isn't obvious and straight forward. Many happen under the vehicle, with the wrong tools, or could be classified as "sketchy repairs in a pinch to get you home". Though they result in really cool stories, repairs that involve welding one of my $50 wrenches to some strangers drag link so they can drive off the trail while risking an accident doing so, no longer seems like a good idea. On my jeep though, a damn good one.

 

[lilscorpion]

To get the front suspension dialed in, we needed to install he fender which are the first powder coated items to be installed and they turned out awesome! Slightly brighter yellow than the factory color but once we get it all on, no one will notice and if they do, it’s close enough that they’ll think it’s intentional.



We spent nearly a day cycling the suspension, moving the tires lock to lock, and making subtle (and sometimes less than subtle) adjustments. Initial fit had the tire hard into the rear fender. This was after we had shorted the front wheel base to what was recommended by TNT. Clearly we need more wheelbase to fit the 40’s.



When cycling the front suspension it’s easier to install a coil on the side you want to droop out but, when cycling the suspension multiple times per side, swapping the spring in and out repeatedly can get tiring. This is where my Eagle jack *****. There’s an adapter that allows me to change the lift height of the jack. To simulate twisting up the front suspension on jack stands, it’s necessary to drop one side almost all the way to the ground but to do so, the jack must be as short as possible. To lift the other side all the way up, it must be as high as possible…which means we had to switch it back and forth between settings every time we used it and to do so, we needed to get the diff back on jack stands…PITA.



A total exhausting game it was but in the end, we managed to land exactly where we were hoping. The only problem we’ve yet to solve is the lock to lock issue. At full lock, the tires just barely get into the radiator housing which isn’t ideal. This may mean that we either need different offset wheels, spacers, or we’ll need to limit the steering. The idea of different wheels is more than Andrew can process at the moment.



One problem we had that we didn’t see coming was the trac-bar was just barely too long. The adjustment was completely bottomed out so the only way to fix it was to whack off a little on both pieces. By removing 3/8” from both sides, I now had just enough adjustability to center the axle correctly.



I hate hate hate cutting powder coated parts. There’s something about it that makes me feel ultra back yard ghetto fab. The only thing that makes me feel better is when I can do it with machinist precision. After marking and cutting each piece independently…money.







We’ll likely need to spend one more day fine tuning but I think we’re really close. As of right now, with no weight in the rear, we’re sitting exactly level front to back which means that we’ll likely need 1” coil spacers in the rear once we get the spare, the rear bumper, and the crusher corners installed. Either way, it’s coming together now and it’s turning out exactly like we’d hoped.

 

[zmotorsports]

Rig's looking awesome Matt.

Thanks for your insight as well. I will post back on my thread after testing so as not to muddy up yours and Andrew's awesome build thread.

 

[bdbecker]

That last pic put a smile on my face - this build is so awesome!

 

[lilscorpion]

That last pic put a smile on my face - this build is so awesome!

I hear you, I’m still smiling. Must have walked out the the garage half dozen times to just look at it. Now any little step feels like good progress.

Thanks for following along.

 

[gearhead1960]

Awesome color! The brighter the better! You and Mike (zmotorsports) have awesome fab skills. I'm envious of your skills and shop.....

 

[lilscorpion]

Awesome color! The brighter the better! You and Mike (zmotorsports) have awesome fab skills. I'm envious of your skills and shop.....

I got some heat from some of my friends initially for picking yellow, like “...but why yellow?”. Now I’m glad, it’ll stand out.

 

[zmotorsports]

I got some heat from some of my friends initially for picking yellow, like “...but why yellow?”. Now I’m glad, it’ll stand out.

I like the yellow on the LJ. I built a 1936 Ford 5-window for a guy about 15 years ago and he wanted it bright yellow. I ended up using the Prowler Yellow with Ford Strawberry Red metallic on the frame and it looked fantastic. I kind of became a fan of yellow after building that car.