Need to torque 750 lb ft counter clockwise

[thejudges69]

I need to torque the bull gear assembly in the front of my Detroit engine. The issue is that I don't have a torque wrench that goes that high. My torque wrench goes to 600 lb ft. I need to torque this nut to 750 lb ft in a counter clockwise method.

So other then a very expensive torque multiplier how else can I achieve this? I was thinking that maybe I could do a torque angle method, like maybe go to 600 and then turn it like half a turn or something.

Suggestions?? I'm doing this today so need input asap.

Also a local tool dealer has the socket in stock but I have to use a reducer to bring it down to 3/4" drive, the dealer says that won't affect my torque but my experience is that it will....thoughts??

 

[doctordirt]

200 lbs at the end of a 3 ft cheater. Not exact, but I think for your purpose would be close enough. Rods and mains you would want to be exact.

 

[doctordirt]

Torque angle will not work. Dealer is right about adapter, no effect on torque.

 

[rlitman]

You need an extension arm.

When the arm extends perpendicular to the torque wrench, there is no change in torque value. When it is in the same direction, it alters the torque value according to this formula.

https://www.engineersedge.com/manufacturing_spec/calculator/torque_adapter_extension.htm

 

[thejudges69]

200 lbs at the end of a 3 ft cheater. Not exact, but I think for your purpose would be close enough. Rods and mains you would want to be exact.

I thought the same. I had my snap on 3/4 breaker bar and a binder pipe to break it loose. I noted the location of the nut prior to breaking it loose. it has some markings on it, I know that's not exact but after torqueing to 600 I could see where the markings are and if I'll be close to turn that far.

 

[thejudges69]

Torque angle will not work. Dealer is right about adapter, no effect on torque.

why wouldn't torque angle work?? I think that's what its called anyways. I need it between 695-750 lb ft.

and thanks for the input on the adapter. I always heard different but good to clarify

 

[thejudges69]

You need an extension arm.

When the arm extends perpendicular to the torque wrench, there is no change in torque value. When it is in the same direction, it alters the torque value according to this formula.

https://www.engineersedge.com/manufacturing_spec/calculator/torque_adapter_extension.htm

I don't think they make something like that in 3-1/4 socket end.

 

[thejudges69]

What I'm rebuilding and why lol.

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[Michael_in_DE]

The adapter won't matter.

If you want it exact, you'll have to contact a local diesel shop, or a local Semi/heavy machinery shop to see if they have one. some heavy machinery manufacturers will have one, (my company does) but it's unlikely they would let you use it.

If there was an easy simply way to do it...nobody would sell the large torque wrenches.

And I am not calling doctordirt wrong... but I have my suspicions that would not work. but if he is truly a Doctor of Dirt, he would probably know more about it than me.

 

[Michael_in_DE]

I thought the same. I had my snap on 3/4 breaker bar and a binder pipe to break it loose. I noted the location of the nut prior to breaking it loose. it has some markings on it, I know that's not exact but after torqueing to 600 I could see where the markings are and if I'll be close to turn that far.

Dude. You cannot reuse the same bolt. That's not what you're doing is it? At that amount of torque you're stretching some threads. Same principle as an axle bolt.

 

[Sevenhills1952]

Would this work?
Your torque wrench goes to 600, you need 750. So torque it to 150. Then go to 300 measuring distance end of torque wrench travels. Now go to 450...should be the same...now 600...then 750.
I'm not saying that will work but thoughts?

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[thejudges69]

Dude. You cannot reuse the same bolt. That's not what you're doing is it? At that amount of torque you're stretching some threads. Same principle as an axle bolt.

This is a non serviceable item from Detroit diesel, so yes I am. It's been done a lot in the field with success, it's a collar on the engine with a large left handed nut. This gear assembly is expensive for the price of 2 bearings. I'm going to include locktite to assure everything holds. The new engine is being built. I need to get this one through a couple more months, and of course if this don't hold, well, the new engine is being built. Not one of my brightest moves, but this engine uses an old style bull gear, with only 12 left in stock in the US nationwide. That is why I don't want to spend the money on a new one, put in new bearings, retorque and run it.

 

[thejudges69]

Would this work?
Your torque wrench goes to 600, you need 750. So torque it to 150. Then go to 300 measuring distance end of torque wrench travels. Now go to 450...should be the same...now 600...then 750.
I'm not saying that will work but thoughts?

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I thought of that as well, but I think as you get tighter, the torque on the nut will get tighter in smaller rotations. I could be wrong of course.

 

[tdkkart]

Dude. You cannot reuse the same bolt. That's not what you're doing is it? At that amount of torque you're stretching some threads. Same principle as an axle bolt.

It's a threaded collar on the end of a shaft, not a replaceable bolt.

 

[thejudges69]

It's a threaded collar on the end of a shaft, not a replaceable bolt.

correct, I'll snap a couple pictures when I'm in my shop, you'll understand when you see it, but no, its not replaceable.

 

[sberry]

I would take it to 600 and move it a pinch.

 

[fordnut85]

The angle method won't work, that is a way to measure bolt stretch to get it to its yield (hence the term torque to yield) bolts. The only way to do this is is with the proper tool. My suggestion would be to call your local CAT dealer or the like and see what they would charge to have one of their field guys stop by and torque it for ya real quick since I assume its in a unit that cannot be taken to them.

 

[larry_g]

If you can get the wrench handle parallel to the floor then you can use your weight. Say you weigh 225lbs. Divide 750/225= handle length or 3.33 feet in this example. If you can't get the handle parallel to the floor then measure out parallel to the floor from the nut center 3.3' and grab straight up (or down) from there.

lg
no neat sig line

 

[thejudges69]

If you can get the wrench handle parallel to the floor then you can use your weight. Say you weigh 225lbs. Divide 750/225= handle length or 3.33 feet in this example. If you can't get the handle parallel to the floor then measure out parallel to the floor from the nut center 3.3' and grab straight up (or down) from there.

lg
no neat sig line

Can't get it parallel. It's a little low in the frame with the tire in the way also. It's gonna be tough getting to 600 even.

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[thejudges69]

The angle method won't work, that is a way to measure bolt stretch to get it to its yield (hence the term torque to yield) bolts. The only way to do this is is with the proper tool. My suggestion would be to call your local CAT dealer or the like and see what they would charge to have one of their field guys stop by and torque it for ya real quick since I assume its in a unit that cannot be taken to them.

Cat may, Detroit does not. I'm sourcing a socket now.

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[rlitman]

I don't think they make something like that in 3-1/4 socket end.

Don't get one with a socket end. Get one that has two forged square holes in your preferred drive size, and use a pass-through square on one end to attach a socket.

 

[thejudges69]

This is what I'm dealing with.

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[Matti]

The first thing I would do is go to an industrial rental shop

 

[Zewnten]

We use a torque multiplyer with a half inch torque wrench. Ours is 4 to 1 so we set the wrench at a quarter of what it calls for. Might be a shop around you willing to rent theirs to you

 

[thejudges69]

The first thing I would do is go to an industrial rental shop

Never thought of that. Good idea!!

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[Mr_B]

torque multiplier handy way. if you got space swing it borrow/rent a bigger torque wrench .
If was marked before came off you could of got proper close just by matching the mark .

 

[larry_g]

Can't get it parallel. It's a little low in the frame with the tire in the way also. It's gonna be tough getting to 600 even.

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Well then go to the second part of my post...

lg
no neat sig line

 

[Wamsutta]

What does the engine go into? I'm curious as heck.

 

[thejudges69]

What does the engine go into? I'm curious as heck.

1992 peterbilt.

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[Wamsutta]

Nice!

 

[rpcraft]

You need to look into a torque multiplier. Not only will it help in this case, but when you need to torque stuff down you can use this to reduce the risk of slip and injury.

I was going to preach about how there is no shame in hiring a wrench when the tool is prohibitively expensive but then I checked on amazon and was amazed at how relatively cheap this one was at 220 USD, lol.

https://www.amazon.com/dp/B0017K5ARU/?tag=atomicindus08-20

 

[sberry]

I would be inclined to buy it before I fukked around renting one. Wouldnt be a bad tool to keep tucked on the truck.

 

[FSrepair&fabrication]

Unless you plan to purchase a torque multiplier or a bigger torque wrench i would pull the bull gear spindle and take it to detroit or your local machine/truck shop and let them torque the nut. Then you can reinstall the spindle thru the holes in the gear. They are torqued to 90-95 ft/lb IIRC. Since you made it this far I assume you are familiar with re timing the engine. Also make sure you install a new crank seal or youll be pulling the cover again in a few weeks.

 

[thejudges69]

Unless you plan to purchase a torque multiplier or a bigger torque wrench i would pull the bull gear spindle and take it to detroit or your local machine/truck shop and let them torque the nut. Then you can reinstall the spindle thru the holes in the gear. They are torqued to 90-95 ft/lb IIRC. Since you made it this far I assume you are familiar with re timing the engine. Also make sure you install a new crank seal or youll be pulling the cover again in a few weeks.

I've not considered a machine shop. I'd have no issue with that. I found out today there is a preload setting for these bearings. Detroit has no method to torque it, I tried that. I thought about trying caterpillar. As for the front seal, yes I have a new one and the seal installer. Thanks for the input.

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[Sevenhills1952]

Here's my reasoning, I'm no expert, mechanical engineer, etc., just a thought, please correct me if I'm wrong.
If you took a large grade 8 bolt and nut (something that could take 750 ft. #s torque. Clamped in large vice.
Now use that 600# max wrench. Torque to 150#. Put wrench on noting exactly where it is, Ok...now torque to 300#. Say it moves 90 degrees or 12". Now go to 450#. Say it moves 60 degrees or 9". Now go to 600#. Say it moves 45 degrees or 6".
Now you have a mathematical pattern. Now you know how many degrees and inches you would have to go to get to 750#.
Where is my reasoning wrong? Wouldn't that work and be accurate?

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[wkndwarrior29]

What others have suggested, Here you go...

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[thejudges69]

Borrowed this from my landscape guy. He works for caterpillar. It's 18:1 ratio. What a breeze. My cdi wrench is bi-****** hahaha. Torques both way so that saved me. It's currently torqued to 756 lbs. I took it to 600 with my wrench and the rest with the multiplier. I have to check the drag on the bearings with a fish scale tomorrow so I gotta pull the assembly out. And just as I hoped. The nut is damn new in the same location!!

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[rpcraft]

Wow, I have never seen an 18 to one. I bet you barely had to breathe on it, lol. I am going to be picking up that amazon one in the future for doing all of the ubolt nuts on my K5. I've watched guys burn up impacts and use the hot wrench, swearing, cussing, etc etc. Seems like the torque multiplier is worth its weight in gold once you start working on buts and bolts that are bigger than one inch.

 

[thejudges69]

Wow, I have never seen an 18 to one. I bet you barely had to breathe on it, lol. I am going to be picking up that amazon one in the future for doing all of the ubolt nuts on my K5. I've watched guys burn up impacts and use the hot wrench, swearing, cussing, etc etc. Seems like the torque multiplier is worth its weight in gold once you start working on buts and bolts that are bigger than one inch.

It's 1" male and 1/2" female. This is cats brand but I think it's a proto and it is like 2-3k new. It was so easy my 5 year old could have done it. I even loosened it, rocked the gear and started over cause I over torqued it the first time. What a breeze. As long and the drag is good, we're gonna build it.

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[intimidator782]

Awesome. Glad you got it fixed up. Ive personally never used a torque multiplier but i bet it would be fun to play around with and would be very handy to have around on hand.