Mine does the same and I have the same trans.. I was in another truck with a pb lvl2 and it sounded the same so it made me feel a lot better. My v6 work truck also does the clunk thing too

 

Well then look at the yoke must be a reason GM updated that thing. Might be that they get some miles on them and start hanging on the tail shaft bushing or something along those lines. If there is anyone in the dfw area who has this prob I would like to check one out for myself just for ***** and grins. See alot of money getting spent and to no avail got to be something dumb.

 

This thread just died? I found it by searching. I have the exact same problem. I was about to replace the steering shaft and see what happens. I think that might be it.

 

Try this first, only $22 on ebay: https://www.performancetrucks.net/fo...d.php?t=402277 Climb under your dash and if a big plastic donut looking thing around your steering column is white, it's the old one and is prone to failure (new one is green). Grab your steering shaft under the dash and see if there is any play to it, if so, replace bearing.

 

I was just under there. Mine is green and has an electrical plug going into it. I was going to remove the shaft and check it out but I couldn't bust the bolt in the column under the dash loose. I'm sure I could have broken it or my ratchet but I quit before it got to that. So I just pumped my shaft a few times like I've read about. I cranked it up, put it in reverse and blipped it and it popped just like before. I couldn't get it to do it again in the driveway but it will do it on random take offs and stops.

It sounds bigger than that little steering shaft. I think I should check the slip yoke. You guys grease that? I have some high vacuum silicone grease that should be very durable.

I think it could also be some frame flex or something. I haven't heard of the cross member under the engine causing problems on the 4wd trucks but I'm going to check mine anyway.

I haven't found one thread where someone said they actually solved this problem. I'll try not to be like that. If I ever figure this out I'll post what I find.

 

Well, Mine turned out to be the slip yoke. I just removed the driveshaft, squirted some grease down into the splined area and put it back together and it really seems to have solved the problem. I couldn't get it to pop on a pretty good drive. I was trying, too. I did use cheap grease so if it comes back I'm going to pack it with some real nice high vacuum silicone stuff that I use for work.

I should mention, I tugged on a few things and tried tightening a few things but nothing was loose to begin with. The only thing I found that was suspicious was a shiny edge on the balance weight on the front drive shaft which is pretty close to the header. I need to investigate that further. So it's not impossible that it was making contact before and that tugging on the header got it far enough away that it didn't do that on this trip. But I don't think that's what it was.

 

Good to hear!

 

mine basically just went away lol..between the new lowering kit, greasing the slip yoke, and the warmer temps its gone..it hasnt clunked in months...

im guessing mine was the slip yoke like others have mentioned...

and my front driveshaft weight rubbed on my headers, so i just ground the weight off...i havent had any problems with it and they have been on for a year now

 

Also check your motor mounts that will make a clunking too. Similar to a driveshaft slip yoke or a u jnt