I just came upon this site and it seems to be the best i have found for jeep questions. I read through the 27 pages to see if my problem has already been talked about but i found nothing.

My problem started when i replaced my rear axle in my 2001 GC with one i bought from a salvage yard. The carrier bearings went out in my old rear end. The one i replaced it with was from a 2003 GC. The sound only happens when i hit a bump in the road. I cant tell which side it is coming from, maybe it is coming from the center. I have replaced the shocks, crown ball joint, and have double, triple and quad-druple checked to see if there were any loose bolts. I have shaken the exhaust and it doesnt seem to be hitting anything to cause the racket. Is the wishbone at the top on the axle different on a 2003 than a 2001? I was thinking maybe there is play in there causing it.

The noise is really annoying. I just paid it off too, so i have lots of plans for it, but this noise is driving me crazy. If you guys can give me some ideas i would be grateful. Thanks in advance.

 

check everything back there. are the emergency brakes hooked up on both sides? what about the brake line junction block, is it bolted to the axle tube?
are the bumpstops tight? pinch clamps tight on the coils?

dunno, you'll have to check everything that was touched during the swap.

 

The sound actually sounds like something rattling against the bottom of the body. i have checked the e brake, and everything that has to do with the brakes. Where are these bump stops and what do the pinch clamps look like? It really sounds like the wishbone is loose. The rubber pieces look fine. Do you think that the size of them are a bit different causing some play. When i replaced the crown ball joint it seemed to change the sound some. Now this just could have been me though. I plan on taking it to the shop and breaking the ball joint loose again and see if the wishbone is loose even though the bolts are tight. The sound i guess is more like a clunking against something more than a rattle.

 

don't quite understand what you mean by the wishbone or crown ball joint.

the spring pinch clamps are little tabs that bolt down on the bottom of the coil, clamping it against the axle spring perch. the bumpstop is inside the coil spring to limit the travel so the axle/tire doesn't contact the body.

could it be the exhaust? maybe the heat shield?

best idea is to take it to a reputable shop. not one filled with apprentices.... for best results.

 

The wishbone i am referring to is the "A arm" or control arm above the rear diff. On top of the diff there is a ball joint that bolts to the control arm. There is no sense in spending hundreds of dollars taking it to a garage when i am just as capable of finding and fixing it as they are. I was a mechanic at a garage before the Navy.

 

Boy, was i wrong...

 

i don't have any experience with the newer grand cherokees.

i did a little online research, and seems that the rattling is common on your year of grand.
it turned out it was the crown ball joint thing on top that you described.


so, good luck

 

I'm working on a 2001 Grand, same thumping over stutter bumps that sounds for all in the world like a worn link bushing... the top wishbone bushing were shot, I replaced them. The lowers inspect fine, no signs of looseness or contact marks. Top ball joint is tight. Exhaust is clear. I replaced the shocks with Reflex, I'm very suspect of the new shocks right now. I think the shocks are making noise. 30 year mechanical veteran here, done lot's of repairs, troubleshooting, etc. The truck has 185,000 well maintained miles. Rough rural roads the whole way. This one is breaking my *****. Looking for emperical data here.... TIA

 

I would start by getting the rear tires off the ground and then start shaking and kicking stuff. Wheels, muffler, cat, pipes and like that. If you cant recreate the noise at that point, then with the tires still off the ground, lift the body up to take the weight off of the suspension, start shaking and kicking things again. This is how I find all my rattles and have always found the noise.
But this is on a GC and mine is a XJ. Should be the same idea, if you take the weight off of something that is lose, then it should move when you shake it. BUT BE CAREFUL! Safety! Safety! Safety! If you still think that its your shocks, put the old ones back on. See if it still makes the noise. Just my two cents. Please do let us know if you find it and tell us what it was.
Thanks and good luck!

 

I finally took my jeep to a 4x4 mechanic. He was able to fix it and it only cost me like 40$. He said the shock mounts were very loose and was causing the rattling. So I think you are on the right track by looking at the shocks. Good luck and let us know if you get it fixed.

 

that doesnt seem like a nice thing to say

 

Well some people join seeking that "Instant miracle cure", and they're disappointed (or worse) when it doesn't work out that way.

 

The top shock mounts... the low grade shocks had thin, rolled inner sleeve in the eye bushing, have had pushed into the outer bolt hole, worn loose. The shocks I got to replace them have a much thicker, machined inner sleeve that will seat better against the mounting tabs.

 

If you noticed, but obviously you haven't bothered...no one replied to my question and that is why i wrote that, but it only shows me that you still didn't bother to look because i wrote that a few months ago.

 

hahahahaha