Recomended bump stop length

cal said:

On my jeep, we cut the delrin rod to a length where it will hit with 3/8" shock shaft showing. The delrin is good for about one season (it chips) and has to be replaced. I keep a dozen of so pieces sitting around pre-cut, and swapping them out is part of our race prep. On the lift it takes me about 3 minutes.

It happens that I work for one of the biggest plastic distributors in the country, so replacing the delrin 3 times a year costs me less than buying a bit of steel tube.

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wanna sell some of it ??

Chipping may be an issue for your use...but for me, where the most off roading mine sees is hunting roads and an occasional romp across a cut over section of forest....probably last me a while, or at least longer than it does you....LOL

My current stock uppers are shot, and while I have brand new extended length uppers here (package ain't even opened yet), I am thinking this may be the way to go, and may even work out to be cost effective also.


I is getting old and prefer a softer ride and less harsh bumps.

Thanks for the explanations

cal said:

This route will probably not be cheaper. Id' expect to spend at least $100 before its done.

But its worth every cent. Most guys will compare the prothane's performance to air bumps.

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I was assuming roughly the same cost for the stops I now have vs the 3 ring inserts (not as much lift as you), and was thinking of using new stock bumps for the top, with the rod/plate in the insert underneath

Buy longer and trim it down. If you think you need 3 rings, buy 4 or 5.

I try to set my rigs up with about a 1" airgap until I start hitting the prothane from ride height, and don't forget you're subtracting the length of the OEM upper rubber.

Anyways Dragonlich1961, I hope you got all that!

I just recently ordered some pieces of "scrap plate" with my order from ruff stuff. and I will probably get some scrap 1.5 rod/tube etc from my buddy's shop. I will then make "inserts" for my prothane coil inserts so that they don't get wedged on my bump stop towers anymore.

I am going to do the same for my MJ since I have my old 2-ring prothane coil inserts as well.

I Think I have the jist. OEM style front replacements are not great. use the prothane ring type, and cut to fit. to prevent damage to the insert, a cap needs to be imstalled over the insert or over the factory bumpstop hole.

What about the rear stops? any ideas on those?

Thanks chris

Dragonlich1961 said:

I Think I have the jist. OEM style front replacements are not great. use the prothane ring type, and cut to fit. to prevent damage to the insert, a cap needs to be imstalled over the insert or over the factory bumpstop hole.

What about the rear stops? any ideas on those?

Thanks chris

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Prothane makes progressive bumps for the rear also. But, depending on your setup there are different options.
I have a homemade (not by me) set of 2x4 square tube drilled and sandwiched in between the factory bump and the frame mounting. Works for my needs. YOu could do a combo of the 2 or, just find an extended bumpstop that works.

cal said:

Jack the jeep up.

Remove the coils.

Bolt shocks back up.

Lower it down until you don't want it to go ANY further.

Measure between hard points.

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I followed this procedure and came up with 8.25 inches as the right length for the delrin rod. Unfortunately, my prothanes are only 7.75 inches long. Oh well. I'll run it like that this weekend, with the prothanes serving only to center the rods in the coils, and I'll order up some new prothanes later.

mtbxj87 said:

I have extended prothane front stops. Theyre really hard, youll know when you hit bump. Next time I have the spring out im putting a stock bumps and some spacers at the coil base.

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I drilled a bunch of holes in the last section to help reduce their spring rate. Not as painful to hit now.