I have noticed in my 2006 1500 Mega Cab 4x4 a high pitch howl or whine that seems to be coming from the rear end. At certain highway speeds for extended periods of time it can get quite annoying on the ears. It seems to come and go with varying speeds and disappears usually when i let off the gas. I noticed it a bit when i first bought the truck used about a year ago and have since put approx 30000 kilometers on and has gotten a bit worse during that period. I have kept an eye on the rear diff fluid and it still seems pretty clean and has no traces of metal but im still thinking its time to get an expert to have a look. Just wondering if anyone else experienced something like this or has any idea what it could be?

 

Been there...done that 3 times with my RT. You have bad pinion bearings if you hear it while you're on the gas but it disappears when you're off the gas.

Definitely not a job for a novice so take it to a professional mechanic if you've never made a repair like this before.

 

Turns out i had 2 seized U joints in my rear driveshaft and he said everything in the rear diff looked good. That's a relief! I should get the truck back tomorrow we'll see if the noise is gone!

 

Stupid non-greasable U-joints, ball joints and tie rod ends plague everyone. I hope you put a good set of aftermarket greasable ones in.

Good to hear the axle is fine. Actually, the AAM rears be they 9 1/4", 10 1/2" or 11 1/2" are pretty stout, at least on par with Dana axles. Yeah the 9 1/4s grenade, but it's almost always the POS Mopar LSD that takes them out...