I have a 2002 2500 HD 2wd, 6.0L gas, auto trans w/ 112,000 miles. Original owner. The transmission started making a loud metalic clicking noise when accellerating from a dead stop. Noise usually stops, or is no longer audible, after the trans shifts to 2nd gear. Never has been overheated or used to pull heavy loads regularly. Shifts soft and smooth. No slippage or any other signs, just the noise. Does it daily but not every time you leave a stop. Sometimes nothing. The noise is what you would expect to hear if you stuck a metal coathanger into a fan blade as it was spinning. Sounds like something is hanging in the pan and is slapping the bottom of the pan as the forward gear starts turning. Trans was serviced at Chevy dealer @ 85,000mi. Fluid is bright red w/ no burnt odor. Has anybody encountered this? Frustrated!!

 

Will it make the noise if you power brake it?

Allan

 

No, it only makes the noise if you are moving forward. If you ease off the line, there is no noise. Only seems to happen when there is torque on the transmission and forward movement. when you accellerate and the clanking is heard, you need only let off the gas slightly and the noise stops. Baffeling.

 

my truck is a manual but when the clutch was starting to go out it sounded like someone dropped a metal marble in my tranny. but the clutching on an auto is different. my brother worked in a tranny shop did alot of work with the allisons ill see if he knows what it might be and let you know tomorrow. usually there is atleast a logical spot to start but not with trannys or motors

 

Thanks, nkh34. I look forward to seeing what he might have to say.

 

My 02 Chevy 1500 HD is doing the same thing. Clicking noise when accellerating from a stop. Not as loud once the truck warms up. Did you find the cause on your truck? Thanks...

 

Just got my truck back last week. Took 2 weeks for mechanic to track down the problem. Was not the transmission at all. It was the starter gear was getting pulled, vibrated, whatever into the flywheel as it was turning causing the metallic clanking noise. Replaced the starter and all is well.