scratchkenny

I have a JKUR I am thinking about 37"s. I have a 3.5" lift with bump stop spacers, what size bump stops should I replace my stock ones with? Thanks

Albino Lizard

Rule of thumb is add the same size bump stop as the height in inches of lift. 3" lift = 3" bump stop extension. It doesn't matter if it is on the post or axle.

mhockey9090

You need to cycle the suspension to figure out what is the correct length of bumpstop you need. Thats going to be the best test you can do. You can have people tell you how much they have for their rig, but yours can be different.

A Jeep running a 3.5 lift on 35s will require a different bumpstop than on 37s.

Generally you can pop out your springs to allow your Jeep to compress a lot easier to measure what bumpstop is needed so your tires do not rub and you do not bottom out your shocks.

TheDirtman

Lift height has nothing to do with bumpstop length, that is one of the biggest mistakes people make setting up bumps and shocks. Added bump stop should start with the amount of tire height gained above the hubs from the new tires.

Albino Lizard

Okay. Here comes some math. Please let me know if I'm in the ballpark.

Stock tire size 32". You up to 35's. Increase in diameter is 3". 1/2 of the increase is above the hub so an additional 1.5" of bump is needed.

Then up up to 37's. 2" diameter increase. 1/2 the increase is an inch. So a total increase of bump running 37's should be 2.5" over stock.

TheDirtman

In generic terms you are correct. Actual heights should be used. Of course wheel back spacing, wheel width, and shock length (both collapsed and extended) will affect your bump stop needs sans the reason to actually articulate the suspension if you goal is to maximize articulation.

Invest2m4

And also factor in if you have additional clearance from say, flat fenders. I know people running 37s with 1" of bump stop.