cLUNK

[Silverado Brethern]

about every other time i accelerate there is a very noticable clunk coming from the drive shaft. it almost sounds like there is slack in the drive shaft like it is slapping into a spline. anyone have this problem?

[pull]

well i think i have the same problem, my does it when i put in reverse or drive,one time it did it when i gave it gas to pass a car,ive been told it may be the u-joint or maybe the tranfer case ,im not sure just what ive been told. just hope its not much money to fix it.

[pull]

well i think i have the same problem, my does it when i put in reverse or drive,one time it did it when i gave it gas to pass a car,ive been told it may be the u-joint or maybe the tranfer case ,im not sure just what ive been told. just hope its not much money to fix it.

[rpreston]

U-Joints. Been there. Have a '90 shortbed since new. On my forth set now... Not expensive if you do it yourself. Grab your Haynes manual.

[chuck16]

I was wondering if perhaps it was a tranny mount. Sometimes they can wear out and you might get a clunk when the transmission shifts into gear.

[Silverado Brethern]

the clunk is immeadiatly when i accelerate. i looked at the U-joints and all appears to be well...so your saying that the clunk is a sign that i should replace them before they break or just something i will hafta put up with?

[vnotaro]

Originally Posted by Silverado Brethern

the clunk is immeadiatly when i accelerate. i looked at the U-joints and all appears to be well...so your saying that the clunk is a sign that i should replace them before they break or just something i will hafta put up with?

This is a very common problem! Mine's an 01' and has been doing this since about 2k. GM has put a TSB out on this problem recommend a fix but all to no avail. The dealer says they've tried all kinds of fixes including driveshafts, u-joints and rearend components but nothing seems to eliminate this. It hasn't caused me any problems but it's like a huge thorn in my side!

[Silverado Brethern]

well im just sayin i really dont care about the noise as long as the drive shaft doesnt fall or anything like that...and also every now and then there is a small oil puddle under my rear diff

[vnotaro]

Originally Posted by Silverado Brethern

well im just sayin i really dont care about the noise as long as the drive shaft doesnt fall or anything like that...and also every now and then there is a small oil puddle under my rear diff

That leak is something you should take care of! Loss of rearend lube will definitely cause big trouble. At least that's something you can see and deal with!

[rpreston]

Don't know about vnotaro's post, haven't heard that before but that could be the case. In my case, my '90 shortbed eats them like candy. I think it's because with the short wheelbase the angle of the driveshalf is pretty extreme compared to a longbed or an extended cab. Plus I'm in a lot of mud during the winter in hunting season. Your description is exactly the same as a worn ujoint. Mine usually starts out with a slight pinging sound when you first take off and then gradually over time changes to the clunk. Sometimes it's most notable when shifting into reverse. I've never had one snap completely and I've road a few of them for a long time before changing. Some of them have a grease fitting (IF you get a gun on them, you can't on most) If yours do, you might try that and see if it helps. While your under there, put the truck in neutral and turn the driveshaft with the rear wheels on the ground, there shouldn't be any play in the rear ujoint itself (can be a little in the diff). Turn it back and forth while trying to keep the diff from turning when you do it. Then with the tranny in gear and the rear wheels off the ground, turn driveshaft to check the front ujoint in the same way. They're cheap enough. 30 bucks will buy you a set and they're not that hard to change. Hopefully, that's your problem and not what vnotaro's has in his post. That would s*ck! I'd keep on eye on the leaky diff too. Good Luck!

[rgwierks]

This clunk almost seems like something is binding. I was wondering if the rear calipers are sticking as my 1999 only does this when I come to a complete stop and when I take off then I get this clunk. It does it both in forward or reverse.
At this point I am not to worried about it as it just stays the same

[SpitAndDirt]

Don't forget about weakness' in the 4L60-E tranny. I would agree with everyone esle to change out your u-joints first. The click or clunk as you describe it, should be the first sign that the needle bearings in your u-joints are at their end of service. Cheap piece of mind. Change them. Also check out these two sites for 4L60-E Tranny problems and solutions should you encounter either down the road. http://www.thesurecure.com/parts/parts/SC-4L60-E.htm

http://www.transmissioncenter.net/ex...duty_parts.htm

[warfox69]

I have this same problem! I took it to be fixed while under warante and its still not right. I notice it after i accelerate past 15mph then let my foot off the gas untill the speed drops down to 15mph, then i hit the gas and CLUNK I makes the noise. Its very loud too, and definatly not a noise that promisses good long lasting life of the the parts making the noise.