Bloody Light Whine Starting With Truck Now.....2003 Sierra 2WD

[XYZ]

Probably the differential, outside chance the transmission. Cruising along today, ~ 150-mile round trip, light whine could be heard during driving, and tends to go away with letting off the throttle. I have changed the oil in the diff. on a regular basis, putting synthetic back into it of course, but the truck (2003 Sierra 1500) does have 173,000+ on it. Trans was replaced at 124,000+ back in 2010. No mods, just a basic driver truck. Anyone had a rear diff go south on them?

[Gurrzt]

it is possible your ring and pinion are worn out.

[XYZ]

Did a fluid change 3-4 months ago, everything in it was fine....

[Gurrzt]

Did a fluid change 3-4 months ago, everything in it was fine....

I just had my fluid changed by the gear shop that I purchased my ring and pinion, after draining the fluid out of the differential, they put chalk powder on the ring gear, and rotated the rear wheels around 2 or 3 times, they then checked to see that the chalk was evenly dispersed around the ring and pinion gears. After this procedure they told me that the gears were lashed and meshed correctly.

 

I do not, and never did have a "whine" coming from the differential.

 

I am told that some gear sets "Motive and especially Richmond" are inherently noisy.