Duramax "jerk" when stopping/accelerating

Truck is a 2006 2500HD with the LBZ Duramax.

I bought the truck at 178k, now at 193k. I did notice this when I test drove the truck, but didn't really think anything of it. When I get to a stop, I feel a jerk or clunk. Then when I get on the gas from a stop, I feel a clunk again. It's almost as if there might be slack in the driveshaft somewhere. Shifting into gear is fine, normal driving is fine. It's just on starts/stops. Transmission is fine, shifts perfect, etc.. Wondering if anyone else has had the issue before? I've been driving it since 178k with it doing this but for whatever reason haven't thought anything about it. Want to get it fixed. Ideas?

Motor mount, maybe? I've never had a Duramax, but I've had broken motor mounts on a few vehicles with similar symptoms, more on the taking off than the stopping. Good luck with it.

Check your suspension, sounds like ball joints, worn out bushings, differential, or u joints.

Lot of trucks have axle wrap that causes similar symptoms.

Might check to see if its a 2 piece driveshaft. Sometimes they make a bump feeling when stopping or taking off from a stop! Grease the joint if it is a 2 piece!

Grease the slip joint or joints on the drive shaft. You Tube has plenty of how to videos.

Yep

If the u joints are making that sound REPLACE them. They are too worn out and No amount of grease will fix them. They are cheap and easy to replace.

I'll get under there and grease everything up today to see if that makes a difference.

Something I forgot to add though.. If I pop it into neutral rolling to a stop, it doesn't do it. Just stops normally, put it into drive fine, hit the gas, bump. I also noticed that it only is noticable at operating temp. When the truck is still cold, it's very very minimal or not even noticable

It's not the u joints, it's the slip yokes. You will have to remove the drive shaft and grease the yoke or yokes on the inside. Don't put too much grease in them, just a light thin layer of grease.

Yep, that's got to be it. I looked up what you mention and they describe what mine is doing. Only thing is, I read that greaseing them will only last you 20-30k miles and it will come back.. I guess the only way to fix this for good is to just a new slip yoke? I don't want to pull the driveshaft every 20k miles or less

Yep our two both do it greasing it is a temporary fix it will come back. It’s been doing it for over 200k miles and doesn’t seem to hurt anything.

GM offers a yoke made of nickle that is supposed to fix it.

That's a crummy solution, unless they're offering it as a free replacement for owners, which I'm sure they're not...

So I take it, this is a common problem on these trucks I'm not aware about? I know it's not hurting anything, it's just annoying.

Yes it's common. And yes, GM should have replaced them all. Mine didn't start doing it till it was well out of warranty. Mine seems to do it more during wet weather. GM also offers a special grease for greasing the yokes, but it is pretty expensive. There are Youtubes on how some guys drilled and installed a grease zerk so it can be greased without pulling the shaft.

I don’t know how prevalent the issue is but it does happen and from the looks of this is pretty common although this is the first time I’ve really heard it discussed other than our two trucks.

I owned a 2009 Silverado extended cab and it made that same sound since brand new. I put 150,000 miles on that truck and never had any problems with drive shaft or u joints. Was told at the dealership when I went in for the 1st oil change that it was normal and all the new vehicles do it.

Make sure you clean the splines as well as the yoke as clean as you can get them. I use several red rags and screw driver to get the yoke cleaned out really well. You want to get all the old grease and dirt out. I use this stuff right here and it seems to last for several years. Has both moly and teflon. Years ago this was the closest I could find to the stuff GM supposedly uses. This can is a lifetime supply and pretty cheap.




FYI also inspect your carrier bearing. I just put one on my 2005 ccsb 2wd. All the rubber was wore out and broke. The driveline will wobble and feel strange when accelerating.

I drive an 05 DMAX and have the same symptoms. I've always associated mine with the rear brakes sticking because its fine when cold and wet outside and worst when dry and hot. This rear I changed my front brake pads and hardware because I was tired of the noise when hitting road bumps. With 225K miles my front pads still had plenty of life but the rotors needed turning. I imagine my rear rotors need turning but I'm too lazy for the task.

I have a ‘15 Duramax and mine has a clunk when coming to a stop sometimes as well. It seems like it mainly does it when it’s cold out.

Sticking brake caliper?

Anyone else notice that the clunk doesn't occur when the truck is loaded either with a load in the bed or tongue weight of a trailer? Or is ours just special.

Yours is special. Mine does it loaded, unloaded, whatever. I'm about 800 miles away from hitting 200,000 miles and I honestly haven't bothered fixing the bump. It's a common problem, doesn't do any harm.

It may been in my dads head, but he was saying his was getting worse. I changed the rear dif gear oil this weekend (it was low, but no evidence of leaking) and he swears there is some improvement.

The truck has over 250k miles on it now and it was the original gear oil. It looked nearly new when I drained it so who knows, but the dif was for sure low on lube.