Differential/Lube general question

For manual trans, diffs, trailer and steer hubs, I've used synthetic 75-90 for over 20 years.

 

You should re think putting gear oil in any manual trans. This is not the approved fluid for transmissions.

 

Thanks for the info, but I'll just have to wait for you to tell me why I shouldn't put the same Synthetic 75/90 in it. I'm not gonna waste time looking for a reason.

If you want to explain, tell me also what difference it will make over the life of the transmission.

 

If that’s true then why every time I install a rebuilt manual transmission from Inland it has a tag on it recommending to use synthetic GL 5 ?

 

Eff it, I lied and looked.

I've used this Castrol 75 90 forever. It's in the new Fuller 18speed in my truck right now, and the same oil I used in all of my customers equipment for years.

Can't remember about Weller, but for the full 5yr warranty on new Eaton trans, you have to also purchase an approved oil and clutch, or just an approved oil for diffs.

Every trans I bought included a 5gal bucket of this oil, and usually an Eaton Easy Pedal

 

pretty sure I've always been sold 50w oil for transmission.

And on a normal 6x4 configuration there isn't one axle that drives all the time. torque goes equal to all 4 wheels until one looses traction. any of the 4 wheels can spin. the one with the least traction front or rear will spin.

 

https://www.eaton.com/content/dam/e...nts-product-specification-manual-tcmt0021.pdf

Approved fluid for Eaton product is PS 386 40wt trans fluid and is backward compatible with all models. Prior to that it was 50Wt.

I guess everyone can use what they like. I’d slap my guys silly for putting gear lube in a trans.

 

Both axles on a tandem are always putting roughly equal power down to the wheels.