Clunk on deceleration...??

The XJ (90, AW4, 4.0) has started to make a clunk when I'm decelerating or coming to a stop at what sounds like directly under my right arm.

It accelerates fine, shifts through all the gears, but when I get down to about 20 mph and under and as it shifts down into the lower gears and to a stop it makes the clunk (each gear it downshifts into).

Is this a u-joint symptom or ??? slip yoke?

Might just be your exhaust hitting the crossmember. Sometimes the hanger gets old and allows the pipe to droop too much. The transmission mount may have deteriorated as well.

But my guess is the exhaust.

Nope, not the exhaust. That's all tight. It's drive line related but I don't know where - or enough about - what would cause a clunk. Each down shift it clunks. Trans mount is new (ish). Just started doing this in the last 300 miles or so.

Check to see if the bolts holding the trans mount in have loosened a bit since you installed it. Also check the crossmember bolts/studs. That's about all that comes to mind :dunno:

I could be very wrong, but this is easy enough to check. I had a similar situation where I could get a clunk on deceleration only and it seemed to go away while decelerating in turns. I could feel the clunking throughout the cabin, particularly under my feet and in the center console, which made me think it was the transfer case u-joint.

Turned out to be loose lug nuts on one of my wheels and my rim was slapping against my brake drum. I went around and re-torqued all 20 lug nuts and found a majority of them to had loosened up.

My Geo Tracker did this when i let off gas.Checked everything and found out the u-joints were bad.Push up and side to side driveshaft by hand and if its not tight prob. going to be u-joints

oh... I'm an idiot, check your flexplate bolts too.

No real experience but one of my friends who knows what he is talking about told me to check mine... haven't done so (yet.) But I have clunking at idle, when starting, and during deceleration. Mine are probably a lot looser than yours :roflmao:

If my memory is better than a goldfish's tonight, I will check my flexplate bolts and update with whether it solved my clunking.