Intermittent clunk-clunk-clunk in the rear

[Jerry Bransford]

Sorry for duplicating this from Mechanically Inept but I don't think that forum is visited as often as this forum is and I'm getting anxious for an answer to a problem.

Ok, this is starting to bug/bother me. Once in a while... like once a month or so... I will get this fairly loud clunk from the rear that sounds like it matches the tire rpm. It doesn't happen often enough that I can say what leads up to it. It's like after I've been driving for a distance, 5-10 miles, I'll slow down to turn into a parking lot or off the faster road onto a smaller surface street and the loud (actually a bit scary) clunking starts up.

I've had the rear axle shafts in and out twice for other reasons since it started. On top of that, the drum brakes were replaced by disks, the tweaked factory axle shafts were replaced by Superior axle shafts together with new axle bearings, plus I have new aluminum wheels. So the only thing left is the R&P and Detroit Locker. I think it is axle related because the clunk is rhythmic with the wheel rotation as I drive slowly trying to pinpoint the sound. I've grabbed and shook the rear wheels to check if they were loose, it sure sounds like they are ready to fall off during the clunking sound, but they are tight. New wheel studs too. The retainer plates that hold the axle bearings are tight.

The shock mounts are solid appearing, at least I see no cracks on them, nor do I see any broken welds on any of the brackets for the shocks, trackbar, control arms, etc.

It's loud enough that I KNOW it's going to create a problem for me on the trail... but it only happens every couple of weeks or maybe even once a month.

It's driving me nuts, so if you have any ideas, fire away! TIA!

[Dome]

How about the locker, I know they are they soft lockers, right? but the can may a hell of a clunk sometimes. Just a thought, it sound like you have checked it out pretty good. Good luck Jerry in finding the problem.

[Daless2]

Hi Jerry,

Have you checked the ring gear bolts?

Perhaps a few of them have back out a bit? I have seen this before having the same sound symptom.

You might want to pull the cover and take a look see again. But please don't re-torque them without taking each bolt out and re-applying red lock tight.

Just a thought.

Good luck,

Frank

[JMyerz]

Check your rear sway bar links. My bushings were shot and was the culprit for an awful sounding clunk.

Justin

[Jerry Bransford]

Thanks guys. I had the diff cover off about a month ago and checked the ring gear bolts and the rear swaybar links are heim-joints, no bushings there. I guess it could be the Detroit Locker but I am not sure how to check that out since it seems to be ok 98% of the time. And it's not the normal Detroit Locker clunks and bangs, that's for sure.

Maybe I'll get lucky and it'll break soon to let me know what the problem is.

[Dan-H]

Frank did have a writeup on using FRS radios for detecting sounds a while back...