2006 Ram 1500 SLT 5.7L, whine/noise on deceleration from rear end

[92saturnsl2]

I helped a buddy do a front suspension refresh with new ball joints among other things. He also needs new brakes all around which he'll tackle himself. His latest complaint is that the rear end is making a rough/whine/grinding type noise (I haven't test drove it, so going off 2nd party info) primarily on deceleration. He's convinced it's a wheel bearing going bad, but that doesn't make sense to me as a wheel bearing noise shouldn't just present itself on deceleration. Some quick Googling and visiting forums suggest that the pinion bearing in the rear differential is a semi-common problem on these.

Just trying to collect info before my test drive, anyone know of common problems that might create this type of noise?

 

[MParr]

It’s an 18 year old vehicle. It could very well be in the rear axle. There’s no telling if the gear oil has ever been changed or not.

 

[bullwinkle]

Sounds like ring & pinion gear noise, maybe pinion bearing?

 

[GMBoy]

Sounds like the differential. First step is fluid service and perhaps consider the 80w/140 weight over the 75w/90 that is probably in there now. Synthetic would also be advisable.

 

[Fabulous50s]

Wheel bearings growl all the time usually. The tone/pitch will change with hard cornering as it loads the bearing differently. A R&P noise is usually accel and deceleration based. Pull the cover and change the oil. You may even be able to feel roughness in pinion bearing with it in N and the rear wheels off the ground.

 

[tnt_motorsports]

Agree with @Fabulous50s if you "scrub" the tires like a racecar when you have a bad wheel bearing the sound will change. It sounds like a pinion gear issue in the rear end. It is pretty easy to pop the cover and take a look inside these diff's.

Just my $0.02

 

[Kira]

How many miles are on this 2006? Hass the diff oil ever been changed?
Raise both rear wheels and see if you can feel/hear anything when rolling a wheel.
Then do the fluid service.