clunk upon acceleration

[tigga83]

My 2001 1500 silverado 4wd recently has started making a noise in the rear end when i accelerate from a complete stop. At first i thought nothing of it, but now its just getting on my nerves. I thought it was loose u-bolts, but thats not the case. Its kind of like a clunk, but immediatlly goes away. Anyone have this problem?? Also, my steering wheel feels strange when i turn at low speeds, i can feel the noise in my palms...anyone else?? The truck currently has 27,000 miles and is still under warranty.

[silveradoman]

I´m glad my truck is a 2WD, seems like to much stuff is going on with the 4X4s

[skipr]

Does it clunk when you switch from Drive to Reverse? Or vise versa? Is the noise at low speed turns a groan type of noise? Or like someting is rubbing?

[LT-Z71drvr]

My 2000 Silverado does the same thing. Nobody really seems to KNOW
what the noise is, other than annoying.
I at first thought that I had a sticky rear caliper, but I checked and those are fine. I also thought U-bolts, but those were fine too. It has to be something internally in the rear end, axle assembly.
I know I am not much help, but I just thought I would let you know you are not the only one experiencing this problem.

[skipr]

Originally Posted by LT-Z71drvr

My 2000 Silverado does the same thing. Nobody really seems to KNOW
what the noise is, other than annoying.
I at first thought that I had a sticky rear caliper, but I checked and those are fine. I also thought U-bolts, but those were fine too. It has to be something internally in the rear end, axle assembly.
I know I am not much help, but I just thought I would let you know you are not the only one experiencing this problem.

Your problem is in the differential carrier, the pinion shaft has worn so much that it has slop in it. Don't mistake the pinion gear for the pinion shaft (two totally different parts). The pinion shaft is the large pin that holds the cluster gears inside the carrier unit. It runs through the thrust block and keeps the axle C-clips from falling out as well. Even if you have low miles on truck, check it out or your diff. will evenuatley snap in half. Then you got a whole lot of repairs on top of the diff. Like ring and pinion gears all new bearings/ races, so don't wait! take the rearend cover off and inspect it.

[rut6466541]

My '02 does the same thing it also clunks when I shift from park to reverse or reverse to drive. Is that the same problem if so, is there any way you can elaborate a litte more on the corrective actions? Thanks

[skipr]

Well the rear differential consist of a carrier (the diff itself) with a ring gear mounted on the left side of carrier, it meshes with a pinion gear and the other end is the yoke(this is the end that your driveshaft u-joint hooks to). A few things can cause slop in the unit, backlash, pinion depth, bearing wear. I have found that the gov-loc differential's fail inside the diff. There are alot of moving parts inside diff. The crossshaft or pinion shaft (nothing to do with pinion gear) starts to oval the seat holes in the carrier housing. Eventuatly a complete snap in half of carrier housing, which has a chain reaction. The ring gear is alot harder metal, and since it was bolted to carrier, now it chews and grinds everthing in the rear axle housing. It can also destroy the axle housing itself if your going fast when it snaps. luckly it will probally happen on a right turn, which u won't be going 40 mph +.Take off driveshaft and rotate rearend yoke see how much play is in the rear diff. (dont jack up tires for this test) you want the load on axle for this procedure. I can go on and on about this, but lets take it 1 step at a time.

[KC Chevy Owner]

Originally Posted by tigga83

My 2001 1500 silverado 4wd recently has started making a noise in the rear end when i accelerate from a complete stop. At first i thought nothing of it, but now its just getting on my nerves. I thought it was loose u-bolts, but thats not the case. Its kind of like a clunk, but immediatlly goes away. Anyone have this problem?? Also, my steering wheel feels strange when i turn at low speeds, i can feel the noise in my palms...anyone else?? The truck currently has 27,000 miles and is still under warranty.

I think I had the same problem, if it sounds like you are getting a chirp when you take off then It is in the transfer case, it almost sounds like your brake pads are sticking though. My 1999 had the same issue and by changing the transfer case fluid to GM recommended Blue Synthetic(not sure of the exact fluid name) this was resolved. Chevy knows about it but it doesn't seem like they want to do anything about is until after the warrenty period is up and then you pay about $15-$18 per quart for the stuff. Hope this helps!! John

[LT-Z71drvr]

KC Chevy Owner-
What kind of fluid is in the transfer case from the factory??
Where can you get the Blue Sythetic ??
Thanks for the help!!

[KC Chevy Owner]

LT-Z71drvr-
I am having mine changed again right now, I will get it back tomorrow and I will post what the fluid is called at that point. It takes 3 Quarts for the change. I am sure if you went to the local parts store they would know what I am speaking of though.

[skipr]

Originally Posted by LT-Z71drvr

KC Chevy Owner-
What kind of fluid is in the transfer case from the factory??
Where can you get the Blue Sythetic ??
Thanks for the help!!

It's called Autotrk 3 fluid (light blue in apperance)

[KC Chevy Owner]

Thanks Skipr this should fix the noise lt-z71drvr is hearing.

[KC Chevy Owner]

rut6466541 your problem does not sound like the same thing from what LT-Z71drvr is explaining, I think you either might have U-joint or rear end problems. I jad to have my U-joints replaced already also around 65000.

[hayesbcajh]

KC Chevy Owner...is the backlash/slop issue something the shadetree mechanic can tackle? My Haynes manual just says to have it serviced by a mechanic because it is so complex. And how long can I expect to drive around with this condition? I've gone 35,000 miles so far and it certainly did it before i got it.

[KC Chevy Owner]

Honestly if you have driven it that long you have probably already done some damage to the gears. Although not probably to drastic of damage you could reshim the rearend gears and take out the slop in the gears, you might end up with a little bit of a whine in the rearend at that point though. Re shimming the rearend is not extreamly difficult but it can be a little tedious, and if you get them to tight you can cause more damage by binding them up. There is a mylar film that is available that you use to set the lash between the gears that I believe is available at the parts store. This is very thin but quite precise material that you slip between the gears and set your shims accordingly.