My 2003 3500 QC 4x4 SRW LB HO auto has right at 29,000 miles. I use it to pull my 8500lb travel trailer and a few antique tractors. In the last 6 months it has developed a clunk in the rear diff. This happens under light pedal when the auto shifts. It is very random. It's been to the dealer several times, the first time they confirmed the clunk was in the rear diff. This time they pulled the cover, changed the fluid and sent me home. The last time I was told that a chrysler rep said that was normal. That the gear lash was needed in these heavy duty trucks. When I go back my question will be hows come it was not there from day one, the first three years it did not have the clunk. Any one else having a simuliar problem?

 

I'm having a similar problem with my '05 6spd... there is excessive play in the rear axle. It has gotten worse over the past 6 months. I think it is also the cause of my vibration....

 

Sure it is not the u-joints?? They seem to be a common item in need of replacement on these trucks, although mine have been fine so far.

 

Is this clunk in the upshift or downshift? I have a clunk in the downshift and from what I have heard from Opie who makes the billet 3 gear drums that the older style drum would not release out of 3 gear quickly enough and when coming to a stop it would finally release and causes the clunk.