Poor Boy Fab Shop; XJ Ubolt/Extended Bump Stop Plates

Poor Boy Fab Shop; that’s me, Skully’s at home DIY projects! In this ever crappy economy most of us see an ever depleting disposable income. (Although I will admit if I did have the money I still like to fab my own stuff, its fun and saves money for the more expensive toys.)

For owners of any 4 wheel Drive the secret is to get as big of a tire as possible with the amount of lift you can afford. For XJ owners it can be a pain to figure out how to get the big tires under your vehicle as most lift kit makers state for XJ’s 4.5″ of lift you can run 32″ tires. Problem I find that not so accurate. I have 4.5″ of lift with 31’s and still rub in the front and rear.  The front of an XJ you can cut to yours hearts content to give yourself room. The rear of an XJ is a little more complicated being it is a Unibody and the pinch seam and lower quarter panel gets in the way. Even with minor to major cutting most still do some form of Bump stop extensions, this is also to stop from damaging your rear shocks compressing farther than your shocks can. Some refer to bump stops as “axle snubbers”, but for this article I will refer to them as bump stops.

On the market there are several options that are cheap to the expensive. First you can get extended bump stops $20-$30, but you still need to extend out your ubolt plates to catch them. As with the way a XJ rear leaf spring suspension is designed, when you lift it the bump stop originally would hit the axle, but with a lifted XJ flexing one wheel upwards the spring/ubolt plate comes up and side swipes the bump stop not making it very effective. So ubolt plates that you can buy that are extended out are usually designed to be the extension themselves with adding plates or spacers to adjust. These I see run from various manufactures $55 to $100. If you spend that much money just to extend the ubolt plate out to catch the bump stop, why buy longer bump stops?

I wanted to keep this project as inexpensive as possible and figure out the amount of extension needed built in as I really do not need to have all the adjustment ability at this time. (I am keeping this XJ where it is at for awhile.)

So here is what I started with, $20 for a set of used XJ ubolt plates from “Cherokee Parts Source” a local Denver metro guy that finds, buys, and parts out XJ’s and sells the parts to us lazy guys not wanting to go to the pick and pull places. (If you want his contact info give me your email addy and I can send it to you.) Some Scrap steel from the local metal supply house that charges .50 cents a pound. I figured I needed about 2″ of extension to stop before my shocks bottomed out and the tires would catch the inner fender. I cut the vertical pieces 2″ and the extended out 3″ with corners cut to avoid the shocks. After cutting the peices for all of this , I started to assemble and weld them up.

Didn’t take long to put them all together, clean up the welds, and paint them. Once dry I installed them and took measurements to make sure I had everything where I wanted it. If I need further adjustment I can either buy those extended bump stops or cut off the stock ones.

For the future I might take my old ubolt plates that I took off to put these on and do this project again, but not build in the extension and instead use hockey pucks for 1″ adjustments, but that is another time. Overall this project cost me about $25 and about 2 hours of time with installation, not including cooling or painting time. For those naysayers I might still have to add a top side gusset for strength, but I did beat the crap out of them before cleaning and painting with a 3lb sledge while they were clamped down and they seemed pretty strong………time will tell.

Here is what they look like all cleaned up, painted, and installed;


  1. Very nice, Which metal supply shop did you go to. Thanks

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