1.5" bumpstop extension from top or bottom?

[Jeff d]

2001 TJ, Rough Country 2.5" lift (installed by previous owner), 31x10.50 BFG ATs on aftermarket rims, and I'm swapping in Rancho RS 5000x shocks. I already swapped in the rears and they ride so much better than the Rough Country. There are currently no bumpstop extensions and the original bumpers are completely rotted out.

Anyway, the compressed shock length vs. stock is dictating a 1.5" bumpstop extension. Is 1.5" extension on the front, if added at the top, enough to likely to cause them to interfere with the springs at full droop? The most expedient thing to do would be to get the longer Daystar or Prothane bumpers and bolt them on with minimal need to disassemble other stuff. Do those all polyurathane bumpers that replace the metal cup clear things ok when drooped?

If I need to do pucks on the lower spring perch that's much more of an ordeal and I still have to replace my bumpstops anyway due to the rot.

 

[InOmaha]

I had to do that in the front. Probably not ideal, but I didn't have time to do the other method. I put them in the weekend before leaving for Moab and had a long list of stuff. I may switch it around when I put on new control arms.

 

[imahnu]

2001 TJ, Rough Country 2.5" lift (installed by previous owner), 31x10.50 BFG ATs on aftermarket rims, and I'm swapping in Rancho RS 5000x shocks. I already swapped in the rears and they ride so much better than the Rough Country. There are currently no bumpstop extensions and the original bumpers are completely rotted out.

Anyway, the compressed shock length vs. stock is dictating a 1.5" bumpstop extension. Is 1.5" extension on the front, if added at the top, enough to likely to cause them to interfere with the springs at full droop? The most expedient thing to do would be to get the longer Daystar or Prothane bumpers and bolt them on with minimal need to disassemble other stuff. Do those all polyurathane bumpers that replace the metal cup clear things ok when drooped?
View attachment 325770

If I need to do pucks on the lower spring perch that's much more of an ordeal and I still have to replace my bumpstops anyway due to the rot.

Typically that style of bump stop isn't recommended. They can bend in awkward ways when the bottom spring perch comes up to meet them and can interfere with the spring. Reinstalling the factory design bump stops is ideal. For the front it is best to add length to the bottom of the spring perch. In the rear you can add to the top but if you get too much extension you may want to add some to the bottom perch instead of continuing to stack from the top.

Before you add bump stops based on the shock compressed length, I'd cycle your suspension to figure out exactly how much bump stop you need before a tire contacts the body. you may find you need slightly more or less bump stop. Remember, when setting bump stops you want to have the shock reach its fully compressed limit at the same time your bump stops max out.

Also when measuring for bump stops measure from the bottom of the metal cup to the spring pad and not from the bump stop itself as that will fully compress.

Hope it helps!

 

[JMT]

@Jeff d. @2.5” suspension lift and adding 2” bumpstop up top caused the cup to rub the springs at droop on mine. Plus, that prothane POS will get bent. I’d just do it right and get a stock cup, new jounces, tap the lower perch, and add the bumpstop there.

 

[AMS417]

@Jeff d. @2.5” suspension lift and adding 2” bumpstop up top caused the cup to rub the springs at droop on mine. Plus, that prothane POS will get bent. I’d just do it right and get a stock cup, new jounces, tap the lower perch, and add the bumpstop there.

I've broken stock size urethane bumps. Stick with OEM style rubber ones and add to the bottom.