best gear oil - manual?

I use a blend of Lucas 85w140 and Lucas heavy duty oil stabilizer.

 

I've had good luck with Lucas and Royal Purple. And no, I'm not a Royal Purple fanboy.
I've never tried the Redline stuff. Lucas and RP were both better than the stock fluid. I bought my truck with just under 12,000 miles on it so the Toyota flavored juice was not worn out and didn't look too bad when I changed it but it was noticeably better immediately and continued to smooth out over time. I can only imagine that the new fluid kind of 'seasoned' the wear surfaces over time.
I use Lucas in the transmission and transfer case and something cheaper in the diffs.

 

Let us know when there's a premature gearbox failure using any brand oil, correct viscosity, with correct change intervals. Obsessing about this stuff and chasing after boutique brands is not worth the time. For a MT, it might be worth going for Redline for better shifting, but I wouldn't go further.

 

Agreed. I run Redline as its been suggested in many places on this forum, and I've personally had no issues. Theres a reason it's popular around here. Change it on time and you should be good.

edit. If you choose to go with a unique option, post your results!

 

I buy whatever NAPA is selling, usually their branded stuff.

Except that time I found bearing cage in my 2002 WRX gear oil. I replaced it with BG gear oil. Don't remember the trade name of it though. That transmission lasted another 100k miles before insurance bought the car with 337,000 miles on it.

 

I recently switched to the Ford fluid from redline. Noticeably smoother shifts now. I’m happy with it and will continue to run it in the future. I wasn’t impressed with redline, I replaced the factory fluid with it and noticed no improvement.

 

I run Redline MT90 in my mt and transfer case and Redline

$30 75w 90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w 90 gear oil in the diffs. I’m not sure where the hatred of redline is coming from in the op.

 

Redline makes excellent lubricants. Don't use the RACING synthetic oil in a vehicle with catalysts intact is the only thing I would offer, and then only the engine oil.

 

This is what I've been running for about 3 months now in my 6speed https://ultra1plus.com/transmission/gear-oil-75w-90-synthetic-gl-4.html
Seems to be working just fine.

 

Nah, it doesn't.

 

I’m pretty religious about spending way too much money on gear oil. Like every 30k religious. MT90 for the last 150k and no complaints.

I run heavier 140 Redline in both boxes. Again, can’t complain.