Clunk Sound From a Start and When Shifting

I have a 2000 Silverado K-1500 and it has developed a noise problem. When I start out from a stop and sometimes when shifting I get a metallic clunk from under the truck. Clunk is not the best word to discribe it, maybe a clink of a ching. It sounds like it's under the drivers seat but it could be anywhere. When I pull a trailer the noise stops. It happens while in 2WD. I have had the u joints looked at and they are tight. There is a little play when you turn the drive shaft at the differential, but it's not very much. Something is shifting back and forth and it's driving me nuts. When I come to a stop I am loading up something and when I move it unloads. Any help would would be appreciated.
Thanks,
Sonny

I knew a guy with a similiar problem but his happened alot more often but if remember right he said there is a heat gaurd for the exaust that was hitting his drive line. Might want to take a look and make sure nothing is swinging over and hitting it

had same problem on same truck dealer changed output yoke on trans. after lift and tires also had similer problem installed torsion bars to eliminate rear spring twist causing drivesaft clunk at trans.

had same problem on same truck dealer changed output yoke on trans. after lift and tires also had similer problem installed torsion bars to eliminate rear spring twist causing drivesaft clunk at trans.
I just re-read your reply for March and remember from a more recent post you bought your bars from RCD. I looked on the internet and found several and now I'm confused. I just want to stop the twist/clunk and maybe help with carrying a payload. The truck pulls and carrys great now...I just don't want to mess it up.
Sonny

I just re-read your reply for March and remember from a more recent post you bought your bars from RCD. I looked on the internet and found several and now I'm confused. I just want to stop the twist/clunk and maybe help with carrying a payload. The truck pulls and carrys great now...I just don't want to mess it up.
Sonny

I have a 2000 Sierra with the same problem. I looked on Motoralldata, and there is a TSB on this. The "GM" answer is that due to the multiple tolerances in the drivetrain (Differential, Transfer Case, Transmission, Front Axle) that the clunking is just the resultant slop, or gear lash. I have 82,000 on mine, and it hasn't been an issue so far. I have replaced the U-Joints, using a severe duty type at the back, but like I said it hasn't seemed to cause any problems so far. Hope this helps.

I just re-read your reply for March and remember from a more recent post you bought your bars from RCD. I looked on the internet and found several and now I'm confused. I just want to stop the twist/clunk and maybe help with carrying a payload. The truck pulls and carrys great now...I just don't want to mess it up.
Sonny

if you want to stop twist check jcwhitney for a set of traction springs, i used these first before i installed the bars.this took care of the clunk noise i had on take off and releaseing brake after hard stop, do not help with payload except to eliminate or reduce the amount the springs twist on take off or stop depending on how tight you set them. replaced with bars mostly for looks. hope this helps
[url]www.jcwhitney.com

mjgjr72....is this the part that you put on your truck
http://www.jcwhitney.com/webapp/wcs/stores/servlet/ProductDisplay?makeId=1000107&productId=5193&catalogId=10101&langId=-1&modelId=1001134&storeId=10101
PERFORMANCE TRACTION CONTROL SPRINGS
Fit pickups, SUVs and vans with 2"W or 2-1/2"W leaf springs and at least 20" between axle and front spring mount
Eliminate the spring "wrap" or twist during hard acceleration/deceleration that can cause power loss and lead to spring and U-joint damage or failure!
Prevent violent tire hopping and damaged drive-line components caused by rotation of axle housing and winding of leaf spring
A J.C. Whitney™ exclusive! Great on- or off-roading! Stop traction loss by ensuring tires transfer engine torque efficiently to the ground. Springs work on stock, lowered or lifted trucks. Precision alloy steel with great-looking, corrosion-resistant red powder-coat finish. Easy bolt-on installation. Effortless tuning. Complete with hardware and instructions. Sold in pairs.

They sell for 69.95. I just want to make sure I'm getting the right thing :-)
Sonny

Sonny01
yes, 2 1/2 measure across your sping to mage sure ,they are real easy to install and made a big differance when taking off and truck brakes slighty better.

OK...I've ordered them and should receive them next week...I'll let you know how it turns out and thanks for all of your help.
Sonny

Well...I installed the springs but it still clunks. Oh well...back to the drawing board :-)
Sonny

I had the exact same problem on my 98 C/K and after a month of searching I found it. The transfer case mount between the transfer case and the cross member was the cause. The mount was fine, But the bolts that hold the mount to the transfer case were loose. It was only a thread or two so I couldn't visually tell at first. I put a jack under the transfer case to check the mount and it clunked so I checked the bolts and low and behold they were not tight. After I tightened them the noise was gone.

Well...I installed the springs but it still clunks. Oh well...back to the drawing board :-)
Sonny
sorry it didn't help, but i hope they help in the long run, hate to have you waste hard earn money.

I tightened the u-bolts at the axle all the way like the instructions say. But how do I know how much to tighten the front bolts.

depends on how much give you want, they are mostly to keep the axle and springs from twisting to much. i'm a lead foot so i had mine almost against the spring, I left a little space to let the spring move over bumps. tighten them up a little at a time and see how it feels.

I have about a half inch between the two springs. I have had them closer and farther apart but I can't seem to tell a differance. What should I be looking for?
Sonny

just how it feels on take off and stops, if you can't feel a difference than don't worry about how much space just leave anuf for the spring to move over bumps and try to keep them equal on both sides.

This might become long winded. The problem is where the driveshaft meets the transfer case. They are made out of two different materials that according to Chevy, binds to each other slightly when you come to a stop. When you go to take off they put apart from each other due to axle wrap causing the "clunk". I had the exact same problem in my 99. It can be dealt with through chevy by replacing the output shaft and drive shaft. Only chevy will tell you that it is not a problem, just a noise. Which is true. This is also a VERY expensive fix. Thousands. The way I fixed it was to completely remove the axle wrap. I have a set of Fabtech traction bars. Rancho, superlift and others sell the dame things. They will however run you between $300 and $500. I GAURANTEE this will fix the problem. Make sure they are installed properly.

found a post on another side and the guy said his transfer case, and tranny mount nuts waer slightly loose and causing his clunk noise, it may be worth checking out on yours

I'm going to look into that on Tuesday when I get my ABS system worked on. If it's not one thing then it's another...