Car lift & extensions...

[Jason280]

I have a MaxJax 2 post 6k lb lift in the shop, and it has been extremely handy over the years...especially with Jeep projects. One thing with the Jeep, though, is due to the lift/tire size, you have roughly 13" of travel with the lift pads until you actually contact the frame (even with the additional 3 or 4" factory extensions).




Here's my question. I'd like to fab up my own set of extensions, but I'm curious how tall I can make them before safety becomes an issue. I know most lifts offer extensions for different height vehicles, so any reason I couldn't fab up a set of 10" extensions and not kill myself? What are the big concerns I may be missing? I have some 2.5-3" solid that I can turn down to fit the lift arm holes, and could even box them in/up the sides to give more support. I guess my biggest concern would be some sort of induced side load, resulting in crumpling/flexing of the extensions.

Suggestions? I don't have enough ceiling height to go with a larger lift right now, and an extra 10" under the Jeep would definitely be beneficial. The YJ and CJ's are no more than 3200lbs, and even my small truck is probably 3400 lbs...so I am no where near max weight.

 

[txvwnut]

The Mohawks we have at the day job have similar style adapters and the longest we have I believe is eight inches.

 

[charbar]

I have four of these made up, mostly for lifting Ford pickups. If you are familiar with them you know that reaching the rear of the frame (especially if they have running boards) requires a tall adapter. Having these lets me get away from stacking multiple extensions and reduces a boatload of sway from the vehicle when the adapters are stacked that tall.

They are made of 1/4" bushing with a few inches of solid shaft plug welded into the bottom of the bushing (plug welded is fine, all the weight of the vehicle is on the outside bushing material, the shaft only locates the extension in the arms). Bottom of the shaft is drilled and tapped so I can tighten the bolt and flat iron to the bottom side of the lift arm to really help reduce sway. They are way safer and stronger than the extensions that came with the lift that I use them on.

Full time mechanic shop here that works on mostly 3/4 and 1 ton diesel pickups loaded to the hilt so these extensions would just laugh at the thought of a Jeep on them.....plenty strong for what you are doing. Yellow extension is one of the originals that came with that lift. Also pictured is the 'saddle' that I use instead of the round pad sometimes.....very handy when you need to get on a frame rail that has a fuel tank mounted right next to it.

 

[finn]

I have four of these made up, mostly for lifting Ford pickups. If you are familiar with them you know that reaching the rear of the frame (especially if they have running boards) requires a tall adapter. Having these lets me get away from stacking multiple extensions and reduces a boatload of sway from the vehicle when the adapters are stacked that tall.

They are made of 1/4" bushing with a few inches of solid shaft plug welded into the bottom of the bushing (plug welded is fine, all the weight of the vehicle is on the outside bushing material, the shaft only locates the extension in the arms). Bottom of the shaft is drilled and tapped so I can tighten the bolt and flat iron to the bottom side of the lift arm to really help reduce sway. They are way safer and stronger than the extensions that came with the lift that I use them on.

Full time mechanic shop here that works on mostly 3/4 and 1 ton diesel pickups loaded to the hilt so these extensions would just laugh at the thought of a Jeep on them.....plenty strong for what you are doing. Yellow extension is one of the originals that came with that lift. Also pictured is the 'saddle' that I use instead of the round pad sometimes.....very handy when you need to get on a frame rail that has a fuel tank mounted right next to it.

I like your concept, although a little supporting engineering calculation would enhance the concept further.

without that bottom support plate to tie things together, just extending the riser seems risky at best, as you’re relying on the thickness of the carriage arm to counteract side loading. The bolted plate should help immensely.

 

[Jason280]

I like the idea of bolting through the bottom, I'll have to see if my arms have holes on place all the way through the pocket.

 

[lolaetype]

I'm very conservative when it comes to safety. I'd call the lift manufacturer and ask their opinion, 844-629-5291.

They make 5.5", 2.75" and 2" extensions. Maybe they can be stacked.

Looking at the the manual they seem to mention the extensions are stackable. The last sentence in the below snip. I'd still verify how many can be stacked with their support people.