For about the last 10,000 miles I have noticed a rumble in the rear end whenever I turn left or right from a standing start. This is with or without a load. I think the tighter the turn, the louder the noise. Could this be a problem in the differential? I changed fluid at 30,000 miles, presently have 46,000. I'm using Mopar differential fluid, nonsynthetic. This is an automatic trans with the factory towing package. I pull a 3000 lb. boat and a 3500 lb. travel trailer, not at the same time.
Any thoughts?

 

Did you get the Mopar friction Modifier for the positract?? I have Dana 70 and I used about 2 bottles of the stuff. Without it I would for sure hear some noise coming from the rear end.

 

I think you need to check the wheel bearing nuts and locks.

 

I'd say to lay off the beans

 

Depending on which diff your truck has, some diffs have a TSB at the dealership. Have you asked the service dept?
Nat

 

Has it been doing this since you changed the diff fluid or did it just start? If it has been doing it since the change, chances are that it just needs the friction modifier.

 

Thanks for all your helpful advice. It looks like I need the friction modifier. I did not add it when I changed the fluid.
Thanks!

 

Get at least two bottles of it... They should be about $8 or so.

 

 

Thanks everybody. I bought two tubes of Trans-X Posi-trac and added them to the differential. I drove figure 8's to work in the lube and drove 15 miles. No more rumbling...
I really didn't want to give up the beans.