Brake Clunk

[Viatcheslav]

I had the same clunk when my VX was lifted by trooper springs (about 5 cm), i mounted the stock springs and the clunk gone!

[mrtew]

Mine has always clunked when I release the brakes and I thought I remembered old threads that said everyones did that and it's normal. It doesn't do it if you brake slowly or almost release the brake right before you come to a complete stop. I think it is the sound of the transmission shifting into 1st gear. If you brake right it has a chance to do it before you stop completely but if not it has to complete the shift the moment you start moving again. That's my theory anyway based on old threads I remember.

[a745035]

My 2001 does it... my brother in-law's full-size Chevy "Gladiator" conversion van does it, my GMC Yukon did it... My Avalanche now does it, and what do all these vehicles have in common? A rear AXLE. (vs. vehicles w/rear independent suspension. My theory is that during moderate to aggressive braking to an abrupt stop, the friction material grabs onto the (pad/disk or shoe/drum style) steel surface of the drum/disk during braking, hard enough to cause a slight axle "wrap" or forward roll just at the point where the last bit of forward momentum happens, causing the axle wrap amd tension it causes to be locked in place by the brakes. Once you let go of the brake, fronts just release, but that "sprung tension from the "wrapped" rear axle being released is what results in the clubk. Next time you hear it, see if you can differentiate where the sound originates, and you'll find (like people have said here) that mild subtle braking to a stop seems not to cause it, while a bit harder braking to a more abrupt or lurching stop seems to cause it.

Sorry this so long, but hopefully the theory helps a few folks have peace of mind for what this is.

Brian

[Knigh7s]

@a745035
I agree with your statement.

I have always had this problem, but I just don't know how to fix it... Does anyone have any ideas for a fix? And its kinda hard to reproduce the symptoms on jack stands.

[Ldub]

Call me a born skeptic, but due to the fact that we don't have leaf springs in the rear, I don't see "axle wrap" as being high on the list of possibilities.
I'm not saying that it isn't suspension related, I just don't think our rear axle is gonna rotate that much.

[tom4bren]

Did fixing your 'waggly rear end' help any with the clunk?

[Ldub]

Did fixing your 'waggly rear end' help any with the clunk?

No Sir...neither did the addn of HD lower links.