Rear end whine at 65 mph, TSB 0045-23

Getting the new diff installed today. But with it snowing here, they won’t test drive it till tomorrow.
I’ll update tomorrow if it was successful or not. I’m hoping so!

 

I'm approaching 25,000 miles on my TRD Sport 6MT and will take this TSB in to the dealership when I have the oil changed. Until now I had just assumed the whine was endemic to only the manual transmission Tacomas; looking forward to not hearing the whine any longer.

 

They installed a new center section assy.
It’s quiet now thank goodness! Hope it remains that way.

 

yeah, had it with the sr5's 15, 17 and my current 22. Interesting thing is not (at least so far -knock on wood) my 22 pro.

 

3 weeks and plenty of highway miles driven since they swapped out the rear differential. It’s still quiet. Zero whine.

 

From what I read here this "normal" Tacoma diff whine is mostly harmonics.
From my years driving and shade tree mechanic, such a differential whine usually indicates an incorrect set up lash and potentially early failure.

I recently did 60,000 mile 4WD Drive Train fluid changes and found no noticeable metal cuttings in the old oil or on the mag drain plugs. Used Valvoline Syn 75W 85 and the whine is still present under highway speed deceleration.

My question is, is there any potential mechanical hazard (failed differential) associated with the whine?

 

Not sure. I drained the rear diff and refilled it when I first heard the noise. Slight metallic stuff in there but I figured since that was the first fluid change since new, it may be expected. Drove it another 5,000 miles or so and had the dealer look at it. They drained the fluid and said it had excessive metal in the fluid. So they ordered a new diff. Now it is quiet.