Whistle Above 65 mph, Not Wind Noise

If it's rear diff, which I'm not saying it isn't, why wouldn't a full replacement fix the issue for half of the repairs?

I noticed it very very subtly at 43-44 mph, and, then it's very prevalent at 84-86mph.

Is that how yours behaved?

 

I'm not a mechanic, so while I can use logic, I can't offer a professional opinion.

1. Noise is coming from front side of the rear diff, see my other posts with photos and video.

2. Yes I'm hearing same whining noise around 40 and 80mph, same as all others.

3. My only explanation is that whoever manufactures these rear differential units for Toyota, keeps making defective units that don't have the gears aligned correctly or something else defective which keeps making the whining noise.

Some rear diffs are made good, some are not and whine...

I don't have any other explanation.

4. What else could it be?

A. Transmission - no, noise is coming from front of rear diff.
B. Drive shaft? Idk, I'm not a mechanic, maybe it has to do how drive shaft connects to the rear diff? Idk how it works or or connects. Nobody floated this theory before on this forum nor elsewhere.

C. When I got back to the dealer and told shop Forman the whining noise is still there, he said "oh so I guess it wasn't a rear differential issue and may be something else". However, no other recommendation and he didn't suspect anything else, and just kept insisting that it's normal for rear diff to make whining noise. He was able to get rid of me.

D. Second dealership I took it to confirmed it's rear differential whining but after seeing that I already had it repaired, they realized that they can't make any money off me and got rid of me saying it's normal.

E. It appears that it's very common for Toyota tacoma and some old Tundra rear diff to be whining without any resolution.

 

Great info. Yes I've also read that this may just be character of Toyota trucks, some do it, others don't but it's not really an issue.

I've seen a few people suspect it's a transmission but I think we'd begin seeing tranny's fail (plenty of 22-23s with high miles) and that's not happening.

I'm going to have my service advisor ride with me to listen but I don't know if I should be in any hurry.

 

Update from me: Master Tech went on a ride with me. He said sounded pretty characteristic for a Toyota diff/truck.

He checked diff fluid which he claims looked good. Checked carrier bearing, drove another 2025 which made the noise and, called Yota engineering/service tech support, all who told him the earlier third gens had a diff issue but parts have been updated for 25s and this noise isn't related and is considered normal.

Told me to drive it a bit and monitor noise, if it changes they'll reevaluate but seems like they did their diligence on it.

 

Now you can find another Tundra that doesn't make this whining noise and show it to the master tech, and ask how come this truck doesn't make this noise and mine does.