Clunk in rear
 

First time posting. Bought my sisters 2001 XJ automatic Sport model with 98k miles and mint condition. She drove it like a girl and it has never been in 4WD. Very little wrong with it that $20 cant fix. Ive owned my 73 CJ5 since new so Im not unfamiliar with jeeps, meaning I have all the tools!

My issue is that I hear a clunk in the rear somewhere when I drive a few feet up an incline in the driveway, brake, put in reverse and thats when I hear it. Drive backwards a few feet and after stopping, I can put it back in drive and the cluck isnt as noticable. Pushing hard on the brake pedal each time makes no difference. I checked the U joints and the look solid, no play in the slip yoke from the transfer case either. I pulled the rear wheels and the axles have the minor end play (normal) and none up and down. The differential looks like its never been opened. I going to pull the cover, clean and change the oil etc.

Any advice on what to look for?

Did you check the hanger for the intermediate pipe on the tranny/TC crossmember?
Sometimes the clunk it the exhaust.
Also some attribute to the slip yoke needing to be regreased.

https://www.cherokeeforum.com/f2/how...erokee-242834/

That fixed a clunk I had. I used a toothbrush to get the splines sparkly.

Ditto on the exhaust hangar. My son's TJ had that same loud clunk and we thought the rear end was coming apart and it was just a loose exhaust bracket. Doesn't mean it can't be something else, but never rule out the little things.

I used to swear I had a clunk just like you described, I did a few transmission drain and fills and the clunk disappeared.

My clunk was extremely mild meaning I was the only one that noticed it, my wife never did.

-Eric

Thanks, Ill start with the obvious like the exhaust hangers, The yoke lube is next as the U joints are original so Thats something to be done as well.

A question. On my 73 CJ all the u joints are the same, front and rear. Is it like this on an 01 XJ? I get conflicting info when i look it up from suppliers and a Moog rep didnt know!

The XJ driveshaft U-joints are 1310 series. Also, when you pull the diff covers to drain the oil, refill the front with 80W90 and the rear with 80w140 GL5.

It won't cost you much to do a couple drain and fills on the transmission, you can get the valvoline DexIII/Mercon at Walmart, like 15 bucks per gallon, and you will use about a gallon (give or take) every time.

Also, check the exhaust thoroughly. I swore that I had a transmission noise in reverse in my pickup, and that it was about to go. I put it in reverse, held the brake while my dad listened. He then gently kicked the tailpipe with his foot, which made the noise disappear. Had a good laugh at that one.

And also where the exhaust pipe passes over the transmission support bar. There's not much clearance there, and if stuff sags just a little bit the pipe hits the crossbar.

I guess thats next after I replace the u joints, change diff fluid and grease the yoke.

Off hand, is there a filter in the 2001 XJ auto transmissions? I may just pull the pan too. And would you know it the solenoids are problematic and should be replaced while its open?

If it ain't broke, don't fix it (solenoids).

The filter is just a screen and only "filters" relatively large debris.

Most people just change the fluid without dropping the pan. I periodically drop the pan (like every 5-8 years) just to see if there's any metallic dust, gears, etc. sitting in the bottom. Probably not needed. If it's NEVER been done might be worth it to take one look.

To roughly quote Cruiser54 - Don't bother changing the transmission filter

It's just a mesh screen so if you really wanted, you could just clean it out by spraying some cleaner backwards through it. When I had to change my solenoids at 110k ish, I did my filter as it came with them but my old one was perfectly fine. Now, my solenoids had been sat dormant for 7 years and failed roughly 4 months after getting it up and running again. Unless you suspect something is wrong in there, it's only worth draining and refilling and leaving it be. Just for the added info, I got my solenoid kit with filter and gasket from I think USA Industries on eBay and have had no issues nearly a year and a half later with daily driving.

And the downside(s) to dropping the pan are:

The dipstick tube can be a monumental pain to separate and you end up spending hours wrestling with it; and

The solenoid connectors are in a very vulnerable place and if you yank the pan too far laterally you can break off the connector parts (although you can solder the connectors on to keep them secure if that happens).

^^

My pan slightly deformed getting the tube to separate, nothing a slight hammering coudln't sort out.