*Clunk* & special 2WD question (spindles)

THIS IS A 2WD JEEP XJ - stock (sort of) - no lift, no suspension mods at all - 29.5" tires (235 series)

I have a clunk noise that is very specific & apparently NOT the trackbar. I worked with some folks at jeepforum.com, & it appears that this type of brake pad wear is the chief symptom of the problem (picture included): http://www.jeepforum.com/forum/showpost.php?p=890044&postcount=25.

It is the caliper that does the clunking. This post explains what's wrong (the caliper mounting tabs): http://www.jeepforum.com/forum/showpost.php?p=902232&postcount=64.

This problem not only causes a *clunk* but it also causes my brakes to wear unevenly (the pads especially, & I think the calipers are going bad, too).

I will probably find the answers to most of these questions when I start to take the front end apart, but it is my DD, so I'd like to plan ahead--

Question 1: are the caliper mounting tabs part of the steering knuckle?

Q2: on a 2WD, to replace the spindles, do I have to replace the steering knuckle? That is, is the spindle a single unit with the knuckle (is the spindle permanently attached/welded to the knuckle)? Or do I replace the spindle separately from the knuckle?

Q3: should I replace just the knuckles, or the spindles too (assuming they are separate parts on a 2WD)?

Q4: does anyone have part numbers for what I need?

Thanks in advance for any help.

The spindle/steering knuckle is a one piece unit. The part numbers for an '88 model are 53002 931 (L) and 53002 932 (R). I don't think they changed through the production, but the dealer would know for sure.

I had a clunk from my brakes too. It got so bad that they would start to clunk on their own when the brakes reached a certain temp. I noticed some movement in the calipers and saw that they weren't resting evenly on the spindle. I had two guys look at it to see what they thought and they couldn't find anything wrong. I even took it apart myself and found nada. I took it in to a third guy and he said a spacer was sticking, causing the caliper to get cocked. I'm not sure exactly what he was refering to but he freed it up and no clunking whatsoever...the brakes feel tighter too.

Might be something you wanna think about before buying expensive parts.

tlman said:

The spindle/steering knuckle is a one piece unit.

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Thanks very much, & thanks for the part numbers!

rumblebelly said:

I had a clunk from my brakes too. . . I took it in to a third guy and he said a spacer was sticking, causing the caliper to get cocked.

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Yeah, we covered the spacer issue on jeepforum.com--the spacer is another method of keeping the caliper and/or rotor from shifting around, but one of the guys said he tried to use a spacer & it wouldn't fit his setup. I haven't tried it on mine, but maybe I'll try it before I change the knuckles.

We also found that putting anti-rattle clips on the bottom brake pad offers a temporary solution. I'm not sure, but I think even the spacer is a temporary solution.

I need to fix the root of the problem, because my Jeep chews through brakes too quickly (ruins rotors & pads, & possibly calipers, just because the calipers shift around so much). At least, I think this is what's going on.

I'd love to find a trustworthy mechanic to fix the problem, but I haven't had any luck, & cannot afford to keep throwing money at this problem for what turn out to be just temporary fixes. (P.S.- I bought this XJ used, so the previous owner might've damaged the front end once, somehow). But maybe you're right--after all, the spacers should be cheap. I'll look into it. Thanks!

My mechanic said he FREED UP a spacer which was sticking. Unfortunately, I have no idea what spacer he was talking about. My caliper had a lot of play in it but nothing looked worn yet...I think I caught it early enough. I'll read through your posts more closely but it sounds like your car was making the same sound as mine. I have no idea what the 2wd set up is like though.

A friend of mine thought anti rattle clips would be a solution for me as well but there's no place to put them on my caliper (2000 XJ).

dont know if it will help you guys out or not but my 91 was chewing through pads(2WD) i changed the pads and cleaned up the calipers.still nothing.burned right though the pads in no time.

had the epiphany to look at the hardware( the stupid rubber sleeve and the caliper guide pin and voila! there was a nylon sleeve inside the rubber boot that had gone to hell. replaced hardware and re-lubed the guide pin with some high temp grease and *poof* no more problem.

kawijames said:

had the epiphany to look at the hardware( the stupid rubber sleeve and the caliper guide pin and voila! there was a nylon sleeve inside the rubber boot that had gone to hell. replaced hardware and re-lubed the guide pin with some high temp grease and *poof* no more problem.

Click to expand...

Yeah, I think that's exactly what that mechanic did and my brakes. "Guide pin" rings a bell.

Every new set of front pads, I rub the rust and some of the crowns (to smooth out the pits) off the pad guides, a bit with a fine file and/or 100 grit sand paper and then rub some copper paste into the guides. The extra material I file off, really isn't much more than the rust crust. Twice a year, I rub a little copper paste into the pad guides and check the rods.
Uneven pad wear is often a twisted plastic (Teflon) liner in the rod guides for the caliper. Maybe the spacer he was talking about is the plastic sheath in the rod guide.
Some models of Ford use a sheet of copper behind the pads, a dab of brake pad silicon and a sheet of copper, sure quiets down the wet pad squeal.

I just discovered something weird. My brakes started making noise again, lot's of squeaking and the thump started occuring. I pulled everything apart and as I was doing so, I noticed one of the pins fit a 12mm socket and the other was a 13mm. After I got everything apart it was quite apparent that the pins were different diameters but for some reason the threads were the same. The pin with the smaller diam was really sloppy in the bushings.

Looks like I'll just go to the parts start and get new pins, might as well get new bushings while I'm at it.