Rear End Clunking Noise

[Bob Oney]

Apparently, this isn't a serious problem because it has occurred ever since I bought my '99 Yukon 4WD in 2000 with 33,000 miles. It now has 120,000 miles. Sometimes, when I stop, then start out like at a stoplight, I hear a single clunk in the rear end, like something sticks, then releases when I start rolling. It doesn't always do it, but it occurs fairly frequently. Is it the rear differential sticking, or brakes not releasing, or something different? I've had all the transverse gear and other oils and lubes changed, but it didn't affect the clunk sound.
I mentioned it to the dealer service writer once, and he said that these vehicles do that.
Thanks,

[pbsfolks]

Bob; I know this is gonna sound crazy, but check your motor and trans mounts. I had the same problem with my 89 full size blazer.........Good Luck .........Mike

[cbconstruction]

Bob

It is your suspension that is mounted to your axle housing. No big deal mine does the same thing. Drives me up a wall. the torque on the axle when you take off makes it twist. It is called loading and unloading

[goinbig]

It could also be u-joints, transmission, t-case, and many other things.

You can't really narrow it down any more without more information.

And cbconstruction, there should not be any noise coming from your spring perches. Yes the axle will rotate a little (actually called "axle-wrap") and slightly "twist" the leaves, but it should not make any noise....since the are mounted VERY solid'ly to the axle housing

[Bob Oney]

Originally Posted by pbsfolks

Bob; I know this is gonna sound crazy, but check your motor and trans mounts. I had the same problem with my 89 full size blazer.........Good Luck .........Mike

Thanks, but I think it has something to do with the rear suspension, like it was designed for a softer ride which makes it too sloppy to release various suspension components when accelerating. Just a guess. Anyway, after living with it for the past 88,000 miles, I'm just going to ignore it. It's not getting worse; it's just a nuisance sound.

[bcopeland]

I had the exact same problem on my 2001 Yukon XL (my threads were posted about 1 year ago here). Took it in and the rear housing had a few loose gears and other things in it. At a red light, when I accelerated, I would sometimes hear a "clunk" and sometimes (most times) I would hear a "whirl;, whirl, whirl" that got faster as I went faster.

[Bob Oney]

Originally Posted by bcopeland

I had the exact same problem on my 2001 Yukon XL (my threads were posted about 1 year ago here). Took it in and the rear housing had a few loose gears and other things in it. At a red light, when I accelerated, I would sometimes hear a "clunk" and sometimes (most times) I would hear a "whirl;, whirl, whirl" that got faster as I went faster.

Thanks. My problem may not be the same as yours -- I don't have the "whirl" sound, and because it has been evident for the 5 years/88,000+ miles I've owned it, I'm going to live with it. May keep it 2 more years to about 150,000 miles unless a great deal comes along. I really haven't had any trouble with it in a long time, but my fingers are crossed.