Mechanical Clunk

[kacyk]

This morning I started up the car and drove about a 100 feet to a stop sign. Just as I stopped there was loud mechanical "clunk" from the engine bay. It almost sounded like the tranny was engaging in some weird activity. The car did not lurch but whatever it was didn't sound good. I did not find any leaks and the car drove perfect. Any ideas or similar experiences? Are the tranny's on these trucks good or ? I'm not sure it was transmission related but I'm not sure what else it could have been.

[kacyk]

This morning I started up the car and drove about a 100 feet to a stop sign. Just as I stopped there was loud mechanical "clunk" from the engine bay. It almost sounded like the tranny was engaging in some weird activity. The car did not lurch but whatever it was didn't sound good. I did not find any leaks and the car drove perfect. Any ideas or similar experiences? Are the tranny's on these trucks good or ? I'm not sure it was transmission related but I'm not sure what else it could have been.

[kacyk]

This morning I started up the car and drove about a 100 feet to a stop sign. Just as I stopped there was loud mechanical "clunk" from the engine bay. It almost sounded like the tranny was engaging in some weird activity. The car did not lurch but whatever it was didn't sound good. I did not find any leaks and the car drove perfect. Any ideas or similar experiences? Are the tranny's on these trucks good or ? I'm not sure it was transmission related but I'm not sure what else it could have been.

[Arizona Hummerboy]

It sounds like it try to go into 4 wheel drive, I know when you go into 4 wheel drive it makes a very loud noise.
You may want to take it back to the dealer ship and have them check it out.

These trucks are always in four wheel drive. It could just be some slop in your driveshaft. I believe there is an updated driveshaft for this problem(not sure though). I had a similar noise and it was fixed with a computer reprogram.

[kacyk]

They ran all the diagnostics and nothing. I hate when that happens! So I made myself feel better by having them install a Corsa Sport Cat Back System with Dual Tips. I feel a lot better now.

[KenP]

Now you can't hear the clunk. Very smart thinking.

[It\'s a Dry Heat]

I know if I put mine into neutral it will clunk.

[kacyk]

Yesterday morning it went clunk again! It only happens after a cold start and when rolling to the the first stop. Off to the dealer again! Hope this doesn't turn out to be like my Land Rover.

[kacyk]

There's actually a TSB out on this issued June 2003 (TSB 03-07-30-028). It reads, "Drivetrain - Driveline Clunk When Stopping."

The description matches what I encountered. I have an appointment Friday to take it back. I'll let you know if they fix it. I understand that the 4X4 system is a heavy duty equasion on these rigs but an audible "clunk" that I can feel should not be a normal part of the driving experience...at least not on a $55K rig.

If it has a TSB, it's a problem and not normal.

[kacyk]

The work order reads, "Inspected Driveline and found the splines need lube." Apparently if that area gets dry a "clunk" periodically occurs. Hopefully this fixes the problem. I asked if this was "normal." The SM stated that it is not normal but is frequent enough for a TSB to be issued. If you have this, I'd get it checked out, TSB in hand.

[PARAGON]

It's very normal. It is commonplace in all GM trucks and SUVs. The dealerships have tried all sorts of grease to keep it from happening and there is some grease that is more "adhesive" that seems to last the longest.

[Klaus]

Here's the Clunk TSBs:

http://elcova.com/groupee/forums?a=tpc&s=2826088551&f=6706011751&m=838605648 5&r=2826018485#2826018485