noisy diff

nearly at 100k miles and just did my second diff/transfer service. If it doesn't start whining soon, I'm gonna feel cheated. Hell, it doesn't even leak around the flange

 

Hey OP, did you check your differential fluid looking to see if water got in there? A symptom of water in the differential is the sudden onset of gear noise.

 

I would check that diff fluid first.

Second I would check out the drive line u joints. Twice a year I fluid film my truck. Always spray the u joints down like every thing else. Seems to quiet down that howling for some time. So I kinda feel like it is coming from them. You know the ungreasable joints that Toyota says are a lifetime joint.

 

fluid topped off and there wasn't anything that pointed to water getting in there

 

That's good news. Looks like it's just gear noise then. I'm not sure why the noise showed up so suddenly though. You could take it to the dealer but I wouldn't mention offroading, or mudding when you do. I've had 6 Toyota trucks since 1981 and all of them have made gear noise to one degree or another. It didn't hurt any of them, actually I kinda got used to it.

 

The latest TSB did not come out until summer of 2023. So maybe not.

 

guess i'll just have to live with it at this point then. no point in cry over spilled milk

 

There are things that you can do to quiet it down. East Coast gear supply suggests 75w140 gear oil in the rear diff to slow down the noise. From my experience the noise is more noticable with a locker. Your trucks under warranty, I'd take it to the dealer just to be sure gear noise is all it is though.

 

My own experience is that the first 100 miles are the most critical for a differential. In California freeways are everywhere and speeds average about 70-80mph. Every vehicle that I've owned with noisy diffs shared a common experience...I drove them home on the freeway within the first 5 miles. Often the whine didn't happen until about 20k+ miles later. I had an F-150 that took 60k miles to start making noise and that was a HD 9.75" diff. The Ford dealer was right off the freeway...lol. When I started doing two 20 minute heat cycles with full 1 hour cool downs from the dealer lot (this can include the test drive before signing papers) and then avoiding freeways for the first 100 and avoiding 60mph+ for the first 2k miles...I never had an issue.

I brought along a pyrometer when I picked up my 2023 just for kicks. The diff gets pretty hot in the first 100 miles...approaching 275+ deg F. I picked up my truck from a dealer 200 miles away so I stayed in town for the first 60 miles and then took the freeway at reduced speeds from there...not the best case scenario...but so far no noise. After about 400 or so miles, the temps never get above 140.

 

funny enough my ram and avalanche make the same gear whine just not as loud because the engine makes more noise lol. time to straight pipe it

 

i was a pretty conservative driver for the first 3k miles, rpm's never went above 2.5k and mostly drove freeway miles.

 

LOL. All ring and pinion gear sets make some kind of noise. Over the many decades I've gotten used to it. If they didn't "sing" I'd think there was something wrong with them.