Hey guys, I just got this XJ and I guess I didn't test drive it enough. It's a 2001 with only 77000 miles so I'm alittle upset. My problem is when I come to almost a complete stop and sometimes when I start again I get a clunk coming from the back almost like if someone tapped me. I heard someone say that it is a common problem with some jeeps. What is it and is it causing long term damage? I actually called the service dept at a jeep dealership and he said he's not sure and hasn't heard of this "common" problem. THanks for any help

 

Sounds like a driveshaft ujoint. Check the ujoint in between the driveshaft and your rear diff. Bet there is some play there.

 

Check the u-joints. That's where I would start...

 

When I bought my 97 I had this same problem thought it was the u joints but nope it was the brake drums after a while the lug bolt hole wallow out causing the drum to slip back and forth on the lug bolts

 

I read somewhere that it could possibly be the driveshaft unloading pressure and not having grease on the splines to moving freely and that greasing the splines will help. Still researching.

 

My 96 XJ started doing this last winter. If I was coasting really slowly to a stop, or pulling away really slowly it would not make the noise, but any time I started or stopped with enough force to compress/release the rear springs it would make a clunk. Just once. Wouldn't do it any other time. I was really scared it was my gears, but it ended up being something way more easy/cheap!

I took my rear driveshaft off and replaced a u-joint that had a tiny bit of play. This did not solve the problem (but glad I did it anyway). What I did next though completely eliminated the problem. I took the driveshaft off again and cleaned up the slip-yolk splines, then repacked them liberally with grease, then put the d.shaft back on. I did this a few months ago and haven't heard the noise since!

I like to fix one thing at a time, so I know what fix solves what problem/noise. Now I know what a dry slip-yolk will sound like when it isn't slippy enough, and it sounds just like what you've got.
Good Luck!

 

This is what fixed the clunk on my 01 xj.

It is a common problem from what i have seen. I have owned two xj's that had the clunk, and my brothers 01 had it too.

Grease up the slip yoke

 

Sweet!!! I'll start there then. Do I grease where it goes into the TC or the rear axle? What kind of grease do I use and how much? Thanks

 

I'm very thorough so some people might say this is a little overboard... but I took the drive shaft off by unbolting the 4 small bolts that hold the U-joint straps to the rear pinion. I think they were 5/16 hex. This allowed me to pull the driveshaft down and then back to slide the front off the TC output shaft. The splines are on the front of the driveshaft. I took a toothbrush and some degreaser, cleaned out the inside of the driveshaft yolk where the splines are on the inside, then I scrubbed the TC shaft & splines until it was clean. It had a lot of dried up grease and dusty crap in there. Then I took hi-temp wheel bearing grease and slopped up both the male & female pieces really good where the splines are. Then I just slid the driveshaft back onto the TC output shaft, then bolted up the u-joint straps and that was it.

It was a little difficult to get the driveshaft to slide forward after I took the u-joint straps off, because the slip-yolk splines were so dry and sticky. I slid a long screwdriver in between the rear pinion yolk and the u-joint to pry the shaft forward. This and a little bangin around with a rubber mallet helped to free up the driveshaft enough to slide it forward & drop it down so I could slide it back off the front part. This was the hardest part and not that hard at all!

If you have a U-joint press (45 bux online) and some u-joints (Spicer 1310 x2) it would make sense to do them too while you have it out. Especially if the ones on there are old or dried out and ungreasable, like mine were. Mine took about 2 hours to take apart twice to replace a u-joint, and then to grease the splines.

One word of caution: When you take the rear of the driveshaft off, be careful you are not under the driveshaft, because it will swing down suddenly if not supported when you get it to slide forward!!! (I was surprised, it wasn't as heavy as it looks.)

 

thats what i had at 120k miles... grease and like brand new

 

Thanks everyone for the help. I'll try greasing as soon as I get a chance. Just sucks cause it only has 77,000 miles and I wouldn't think this would happen so early.

 

ok, I have had this sort of clunk for a long time I am not sure if it's totally coming from the rear of the jeep. I see your talking about the front of the drive shaft so does the sound come from there? It only seems to happen when I come to a complete stop and then give it gas, I always thought maybe it wasn't shifted into 1st and that is what it was but after reading this it sounds like it could be my drive shaft...
Thanks,
Lee

 

I would imagine it's more of a maintenance thing than a wear thing. I could see the problem developing even after just 20K if it sat for a year in a dry, hot climate and all the grease dried out, or someone took it swimming on a regular basis or something. Maybe yours sat unused somewhere for a bit and that's why it's low mileage too? If so, I'd say it's a worthy trade, a little greasin for an XJ with under 100K!

Mine has 195K and doesn't seem to wanna quit... you should hear the noises I call "normal"!

 

I couldn't isolate my clunk to that specific an area since it's kinda hard to listen under the jeep while accelerating or braking and that's when I heard my clunk. I heard mine coming from under the vehicle, behind me while driving that's about as specific as I could get with the sound. What helped me find it was realizing it was linked to pressing or letting off the gas which started me checking the rear driveshaft.

I had a bad U-joint in there also, so those are worth a wiggle while your checking. I've often wondered if the sticking slip-yolk wasn't to blame for that u-joint going bad since the U-joint looked pretty new but was definitely showing visible wear inside the cups.

When I was researching the noise a while back, I also read about the same symptoms coming from rear shocks that were old and were kind of sticking if I remember right, so maybe take a look at those too while you're under there.

 

i hear that, LOL. 186k on mine...but if I can get rid of some "normal" noises with a little greasing that would be great.