Clunk when leaving a stop.

[thompsoj22]

Transfercase planetary? are your tires all evenly matched in size and pressure? Allthough pressure difference would have to be dramatically low/high so not likely. The transfer case design keeps all wheels driven all the time and has a planetary that allows stabiltrak to do it's thing. If the planetary were failing it could be creating a drag on the front diff and giving you that wierd steer problem and would be making noise as it is about to grenade. just a thought, have the tires allways been matched in height?

 

[PatDTN]

Transfercase planetary? are your tires all evenly matched in size and pressure? Allthough pressure difference would have to be dramatically low/high so not likely. The transfer case design keeps all wheels driven all the time and has a planetary that allows stabiltrak to do it's thing. If the planetary were failing it could be creating a drag on the front diff and giving you that wierd steer problem and would be making noise as it is about to grenade. just a thought, have the tires allways been matched in height?

Mine is a Tahoe with 4 wheel drive, not AWD. But at any rate all my tires are matched and the pressure is spot on. Thanks for the thought though.

Pat in Tennessee

 

[sneasle]

I'm having a similar issue, but my 'clunk' is also accompanied by some hesitation.

When pulling away from a stop (sometimes), I'll feel the truck hesitate a bit (it does start to move, just not at the rate I'd expect), and then I'll hear a clunk and feel a jerk from the driveline as it surges forward a bit and then starts to pull normally. I find that coming to a harder stop is more likely to cause it on the re-start. I also find that I can prevent it from happen by pulling away from the stop very slowly.

Originally I thought that the slipjoint in the yoke/shaft might be binding, but I'm not sure on that anymore. Might be a u-joint? Could it be the dreaded cracked-engine-mounts-of-doom? I'm also fearful that my 1st gear might be slipping, though I'm not sure how to test that.

 

[bladenbullet]

sounds like suspension but i wouldnt rule out a sticking driveshaft slip joint at the trans either...something like that normally wont change trajectory but if it is binding it can create a torque condition....remove the driveshaft and grease the splines...

i would be concentrating on suspension pushings and the park test with someone looking underneath while torquing in drive and reverse might reveal something...also driving around someone in right circles and left circles torquing on and off the accelerator might aggravate the problem enough for them to see something shift...

hanging on a lift might load an otherwise loose component and make it hard to find play in a position it isnt in when the suspension is loaded...

 

[01subCT]

Check your body mounts.my 01 suburban has the same noise an happens the same way yours does.i found a bad body bushing by the drivers door.the lower part of the bushing was pretty much gone the there was quite a bit if movement.could make it feel alittle loose from side to side I bet too

 

[PatDTN]

I hear ya on suspension droop on the lift but generally if things are loose you find some shiny bits at the bushing locations. Worth revisiting with it sitting on its wheels somehow.

I'm not ruling out anything until I find the problem. There's nothing,more expensive than ignoring one thing and fixing something that doesn't need to be fixed.

 

[George Hoffman]

You might want to check either a, your rear end gears might be going out, that's what happened to my 2000 Z71 or b, make sure the U-bolts securing your rear end to the leaf springs aren't tightened all the same amount of threads and torque.

 

[kbuskill]

You might want to check either a, your rear end gears might be going out, that's what happened to my 2000 Z71 or b, make sure the U-bolts securing your rear end to the leaf springs aren't tightened all the same amount of threads and torque.

07-14 NNBS (which is the section you are posting in) have coil springs in the rear.

 

[PatDTN]

Thanks for you guys keeping my thread alive. Sorry life keeps getting in the way of chasing this. I do promise to update this when I figure out what I'm feeling. I'm leaning toward the engine mounts.

 

[Rocket Man]

Me too.