Suspension noises (clunking)

Hey hey,

Well, I'm beginning to notice some "clunking" in the suspension of my 2001 XJ on some occasions, particularly when hitting bumps in which there is any resulting side-to-side energy transfer. On the front suspension, I found the problem and fixed it last night (worn/rotted sway bar bracket bushings), which was a fun 30 minute project that made things sound like new up there.

Unfortunately, the rear is still making a bit of clunking noises, and it seems to happen at a wider variety of speeds and under different conditions (pretty much any bump). I crawled around under the rear of the truck last night and didn't see anything awry (the rear sway bar bracket bushings looked perfectly healthy as well), so I'm at a bit of a loss. Are there any common points of wear/failure on the rear suspension setup that can result in clunking noises? I very well may not have been looking very hard, as I was exhausted and just getting home, but I'd appreciate any guidance you can give. Thanks!

Campbell

First, I'd check your shock bushings. The upper end of the rear shocks use a bar pin to mount to the shock bracket. It's really common for the bushings to shrink/wear over time and get a small amount of play/slop so any time the rear suspension loads/unloads rapidly (like over a speed bump) you get a clunk. Dunno if you've modified the suspension or not, but a lot of us put in bar pin eliminators (easy to make, search this site- but you can also get some good ones from JKS mfg if you are inclined) that eliminate this problem. It could also be ujoints on the rear shaft, or slop in your slip yoke coming out of the transfer case, but shocks would be most likely. Hope this helps.

10-4, Ghostrider.

I went out shortly after posting this to hit some controlled bumps to get a better idea of exactly what was making the noise, and I think you're spot on. The upper shock mount bushings are cracked, so they're probably quite old (given all the rust I'm thinking they've been in there a while).

Furthermore, anytime I hit a respectable speed bump at ~15 mph, the rear-right side would almost groan (it honestly sounded like a very brief flat/off-key note out of a trumpet, almost comical in nature), which seems to me like it'd definitely be a problem with the shocks since they're the only component I can think of whose design could even allow for that kind of a noise.

On that note, what shocks would you recommend as a hold-me-over until my first upgrade purchases for the vehicle? I'm hoping to do a staged approach to my build, as that's a lot more fun. The vehicle is 100% stock at the moment.

I guess this is my stage 0, so to speak - eliminate all squeaks, creaks, and clunks. I want this baby sounding new.

Update: After some quick research, I'm eying the Monroe SensaTracs... They're available locally and seem to be a good fit for my initial uses of the Cherokee.

Am I on the right track here?

I'm running Monroes with BPE with a 4.5/5.5 inch lift and have no problems.

Good deal. I bought a pair of Sensa-Trac load-adjusting shocks, which should be at my local store within the next half an hour.

Given how oxidized the bolts holding the existing shocks in place are, would it be a good idea to go ahead and replace them with fresh hardware? If so, does anyone know offhand what types of bolts are used to secure the rear shock absorbers? I've been flipping through the Haynes XJ manual but can't find a damned thing about standard bolt sizes and threading...

Nothing in my life is ever simple:





So that answers my question - I'm going to need to install new hardware. Now, however, I'm in a dilemma... I've never sheared a bolt before. What's the best way to go about removing it?

And with any luck, if I make it to the step in which I actually install these shocks, I'll definitely need to know what types of bolts I'll need to use.

Thanks in advance!

search broken rear shock bolt -- nope, no luck. tried rear shock bolt -- all forums instead of technical.


http://www.naxja.org/forum/showthread.php?t=1000024&highlight=rear+shock+bolt

That's all well and good, however, not what I'm asking (thanks for the info though - I bookmarked it for future reference).

At this point, I need to know the factory bolt sizes to do an OE-style shock replacement. Through many comparisons at my local AutoZone, I found that they are 5/16"-18 bolts, however, I'm not sure if I need to use 3/4" length or 1" length. I bought both, so please feel free to pitch in your $0.02 on which ones should be used (hopefully I'll be able to tell after extracting what remains of the old ones).

God dammit.

I managed to drill a 9/32" pilot hole into one of the bolts, got my 5/16"+ extractor in there, and promptly snapped the tip off with almost no force and a small hand chuck (it was the first real twist once it "bit", so to speak).

This is getting to be extremely frustrating. Does anyone have any other tips? I'm going to try to return the damned extractor set I bought and then try to figure it out from here...

Ok, I'm throwing in the towel for the day...

The aftermath is 3 bolts sheared (one successfully removed), two bolts partially cored out but with the tips of bolt extractors lodged in said holes (yes, I broke two extractors today), and one pissed off XJ owner...

With regard to the suggested thread, I attempted to punch out the seized bolt nubs using a hammer and a punch (followed by a screw driver) but to no avail. Do I need to use a pneumatic impact hammer?

Update:

I rented an air compressor and bought an impact hammer/chisel and managed to punch out the 3 sheared nuts without a problem (and fished the replacement nuts in there using an extendible magnet, which made it a breeze). However, I made the mistake of thinking that I should go ahead and hammer out the last remaining nut (which was good - the one bolt that didn't shear off) in the name of replacing all the hardware, so now I have a nut whose threads are being stripped by the impact chisel and seemingly not budging.

What's the best way to handle this? Should I attempt to thread the bolt in there and shear it off using brute force so I have a better impact point?

If I get bar pin eliminators do I need to get new shocks?

You're gonna hate this- It depends. OK, kidding. You can make your own and only change the mount to mount spacing by about 1/2", which means no, you wouldn't to do anything. But if the BPE changes the spacing by an inch or more you should put hockey pucks on the pad inside the coils so that when you hit full compression you won't bend anything.

When that same thing happened while putting a lift on a friends jeep, I took some 3/8 plate, made some new upper plates, drilled & tapped it for the shock bolts, then welded it on top of the old bolt holes.

Worked great, and only moved the shock mount down 3/8-1/2".

Oh yeah, that exact thing happened to me, except I got ULTRA lucky and all four snapped! I ended up doing exactly what Martin over at RockLizard did: http://www.rocklizardfabrications.com/broken_shock_mounts.htm except I did a much uglier job. This was before I considered using this magical "internet" thing to solve my car problems, so it took me 9 hours of drilling, ruining drill bits, and cursing under my Jeep. You want a 1" bolt probably. Mine are grade "crap" (I think it's grade 3, zinc plated whatever they have in the bargain bin) and have lasted half a year with no stretching, but you might want to go for a grade 5 or 8. The easiest way is actually to fish the bolt in from above using string or a magnet like you did, that way it's easier to line the shock up on it.

As for the one remaining screwed up nut, I would either keep at it and punch that sucker out like the rest, or bore straight through it large enough to clearance fit the 5/16 bolt and put another nut behind the old one via your magnet method or Martin's method of cutting through the floor.

EDIT: you'll be quite happy to know (if you haven't done them all already) all your problems with front shocks may be solved via judicious application of a dremel with a cutoff wheel. *ALL* of the mounting hardware is either loose and easily replaceable, or attached to the shock and replaced along with it.