215,000 miles, and it's starting to show...

[Badbird2000]

I have a 2012 Silverado Z71 I bought used in 2014, it had 26,000 miles. It's been my faithful every day driver, pulling my hybrid camper 5 years ago and my 26' TT we upgraded to in 2020. On our way back to Knoxville from Charleston, SC two weeks ago, the rear end started screaming. 100 miles from home, just get us home. Got home, got into the shop, buddy diagnosed it with bad pinion bearings. Great, got it fixed up, drove it home, the transmission started acting funny. Like i was driving over rumble strips.. only i wasn't. I called him on the way home, hey, what does it feel like when the torque converter goes? Like that.... well crap. He was able to get into it today, metal shavings in the pan. Getting a rebuilt with 3 year warranty. I've been trying to find a new Silverado RST with 6.2 and max tow package for last 6 months. Nothing. Guess i'll keep this one together for a while longer. I talked to my locale dealer Friday, as of now they can't even order an RST with 6.2....

[richard wysong]

Circumstances make me wonder if the differential was properly set up after doing the pinion bearings. How much metal was in the pan? Pinion bearing failure isn't that common as the bearings are submerged in oil , was it leaking or low on oil? if they failed enough to make the axle "howl" the ring and pinion would have been damaged enough to warrant replacement. Lots of things related to the driveshaft/ differential can cause that "rumble" other than the trans. To replace the pinion bearings the axle housing has to be "gutted" and then the gears need to be set up anew, a rather involved process that requires quite a bit of expertise

[Badbird2000]

My buddy is a certified GM technician,  I actually met him at the racetrack through a friend. He is very good at his job, I have no doubt the job was done correctly. I had been lax on having regulat maintenance done on the truck, in all honesty. 

[swathdiver]

Keep the truck on the severe service schedule and the new transmission will last even longer.  You did good with the first one.

 

If you're going to keep this truck and tow a lot with it, consider putting the 9.5" 14-bolt axle underneath from an NHT equipped truck.  Bolts right up but all of them have rear disc brakes.

[Grumpy Bear]

New pinion bearings and reused the old 200K+  gears and carrier bearings? 

[richard wysong]

just because the guy is GM certified means nothing as it's just a written test and there are many different areas to be certified in but it's your $ and a good trustworthy tech is a good thing to have so hopefully your not putting a trans in to find out the diff or driveshaft was the problem . I agree with Grumpy the rear diff should have needed much more than just the pinion bearings. Very coincidental that the "rumbling" started when you picked it up after a major repair on the axle, I would be getting a second opinion

[Grumpy Bear]

3 hours ago, richard wysong said:

I agree with Grumpy the rear diff should have needed much more than just the pinion bearings.

 

That many miles there is a wear pattern engrained in the teeth. The chance of getting it back in that same place is impossible. Especially when a bearing is wiped. There is literally no way to establish a reference distance. Noise is the usual result. 

 

A wiped bearing tosses very hard fragments all over the inside. Damage is inevitable to all contact surfaces. You save the housing (hopefully) the carrier, maybe and the axles most of the time. The rest is ghost.