Toyo Koygo 5 lube

[rezmedic]

Will Hypoid gear lube damage the synchros in the TK5?
I read in a few places that Hypoid gear lube will corrode the brass in the synchros.


I plan on putting in 75w90 or 75w145 full synthetic in front, rear and tranny, if I can use same fluid in all 3. Evidently the T-case uses Dexron II, so there is not much to add to it as far as slippery stuff goes, that I know of.

 

[pcollins]

Hypoid gear lube shouldn't damage anything.

 

[4x4junkie]

I've read GL-5 rated fluids are what can damage brass. GL-4 is what you would want for a transmission.

That said, I used GL-5 gear oil in a FM146 for a good several years and in that time never had an issue with the synchros.

Don't put anything thicker than 80W-90 in your trans though if you still want to be able to shift it in the mornings.
Yes, t-case takes ATF fluid, not gear oil.

 

[rezmedic]

Thanks all,

Ok, Thank you all! I was having a hard time figuring out what to use, manual just gives a ford part number and no gear lube bottles had that spec on it.