Like many of you guys with XJÆs IÆve had a mystery clunk in my front end when the suspension cycles. IÆve had the wheels off three times looking at everything. I finally decided to replace the bushings in the lower/upper control arms as well as the track bar bushing.

I started with the lower control arms. The factory bolts were frozen with corrosion and wouldnÆt budge. My Sawsall and a ôTorchö blade took care of the bolts. The bushings were also frozen in the control arms and would not come out even with my 2,000 pound arbor press and a three-foot bar and a lot of PB Blaster. I cleaned out the Blaster after long periods of soaking with brake cleaner and compressed air and then squirted in some CLR and watched bubble for several minutes, it worked but when they let loose it sounded like a hand grenade went off. Save your money up and just buy new control arms if you live in the Rust Belt like I do. A fairly easy job turned out to be a giant PITA.

After replacing the bushings in both lower control arms I took the Jeep for a rideàthe clunk was still there. I decided that I would build a ramp using 2X12Æs by three-feet and 2X4Æs that my trusted helper could drive up on then drive off (carefully) while I would be looking and listening under the front end.

Before doing this I decided to look one more time. I went over every square mm of every component. With a bright flashlight I notice a tiny shiny spot on one of the bolts that hold on the steering box. I have aftermarket ôHi Countryö tow brackets that wrap around the frame and are held on by the steering box bolts. I couldnÆt see or feel if there was any wear on the sway bar but after using a mirror I saw that the paint on the sway bar was worn off. I confirmed the contact by taping a piece of paper to the sway bar and taking the Jeep for another rideàyep, there was a slight tear in the paper. I fixed the problem by removing the washer and grinding down the bolt head about a 1/16th of an inch.

TIPS: If youÆre going to tackle the control arms, do one side at a time. The front axle will move when the bolts are removed. I didnÆt have a tapered rod and a helper at the time so I used a floor jack and a come-a-long to realign the holes. They have to be aligned perfectly to get the new bolts through the holes in the brackets/bushings, especially if you replace the factory bolts with grade 8 9/16-12 bolts (theyÆre a few thousandths bigger in diameter). Leave the bolts/nuts loose (finger tight) then put the wheels back on to put weight on the suspension, then cycle the suspension up and down and sideways several times. Then torque to factory specs (85 ft/lbs.) I torqued mine to a little better than 90 ft/lbs. because I used anti-seize on the threads and nylon stop nuts.

If you replace the factory bolts with grade 8 US bolts use anti-seize on the bolt shafts because if you look at the factory bolts youÆll see that the shafts are smaller in diameter except for about 3/8ö near the cap end and the threads. IÆm sure they did this to keep the amount of contact between the bolts and the sleeve in the bushing to a minimum to prevent seizure (didnÆt work on mine). I found my replacement bolts at a local ACE Hardware as well as some grade 8 nylon stop nuts. Grade 8 bolts arenÆt quite as hard as factory bolts but still have a rating of 150,000 PSI of shear strength and should hold up fine.

Added 05/01
I didn't mention in my original post, because it was getting a little too long, but I noticed that the factory installed the front bolts with the bolt head on the inside of the bracket. When I punched out the bolt (driverÆs side), the head hit the differential. I was able to punch out the front bolts, not the rears. The factory bolts are about 4 1/4 long and since I was replacing them with 4 1/2 bolts I installed them with the bolt head on the outside of the frame/bracket. Also, I hoped that I wouldnÆt need to have a front end alignment done (I recently had it done and everything was within specs) but I have noticed that the Jeep is drifting to the left slightly. I stopped in a local alignment shop was told that even though I didnÆt mess with the shims for the caster (?), I would need to have the front end aligned again. IÆm going to bring it this weekàanother hundred bucks wasted for not being careful enough and throwing parts at a problem.

Good information. Thanks for posting it.

You're welcome John. It's something that I should have caught, but maybe somebody will benefit from my oversight.

Be careful when tightening the steering gear bolts on an XJ to torque them to factory spec, I think it's 75 ft/lbs. Overtightening the bolts will crush the frame rail. Once the inner frame rail sheet metal bolt sleeves have started to crush, the steering gear bolts will continuously loosen. The front frame rail would then have to be replaced, but I think there are now some aftermarket frame rail repair parts that beef that area up and repair a crushed rail.

Thanks for the tip. When I replaced the bolt through the frame I noticed that it was a little looser than when I first installed the tow brackets. I didn't use a torque wrench, but did notice that it was a little "soft" so I didn't over tighten it(I hope). I'll check it next time I'm underneath. Good info.

I am not looking at that potential problem with my eyes... but would a home made 3" washer, made from...say 3/8 in plate, and longer bolts hold it together?
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

What happens on the XJ, (and I think the ZJ too), is that the internal bracing inside the framerail is only thin sheet steel, that is there to keep the frame rail from crushing together when the bolts that hold the gear to the frame rail are tightened. A fix would be to drill all the through holes large enough to install thick wall steel tubing with an ID that would accept the 7/16" diameter mounting bolts, then weld them into both sides of the frame rail, so that the bolts will be once again able to be torqued to spec without crushing the rail. YJ's and TJ's already have thick wall tubing welded in to the frame for the steering gear mount so this is not a problem in these Jeeps.

This is one company that makes a reinforcement kit, that includes sleves for the frame rails:

http://www.c-rok.com/sb.html

Click on the pics to see some typical failures!

Once the original sheet metal bracing has started to crush, it will continue to do so, much like if you dent the side of a soda can, it won't hold weight anymore.