I bought some oil for my transfer case and it is the coastal brand 75w90. it says api service GL-5, GL-4, and GL-3. is this safe to use in the transfer case and transmission? I know in the manual is says to use GL-4 in the tranny, but since the oil is listed as GL-5,4,3 will it still work? I've called everywhere and nobody sell just GL-4 oil. thanks

 

good enuf thats wut i run in mine

 

The t-case needs nothing more then a nice gear lube. But since the seal between the t-case and tranny, alot of guys will run the same lubricant.

I run Amsoil synthetic 75w-90 severe gear in my t-case (same with my diffs).

 

I have a 1990 and the haynes manual said put ATF dexron II in it? I was taken back a bit but I did. It seems to be doing. It is a manual v6...

 

uh, ATF should only go in automatics. Sure you read that right?

 

You sure the manual wasnt telling you to put the AT fluid w/ dextron into your power steering pump?

 

Using the GL-5 in the t-case is fine.....unless the seal seperating the two goes out. If it does.....however unlikely, you'd be draining and refilling anyway to make the repair.

Nevertheless, the transmission will be happier with GL-4. I can't find that locally, either. So, I had to go to the internet and got the Redline MT-90. Consider using it. The brass synchros will love you for it. BUTTERRRRR!!!

 

I read it right and I even made lines going across to double check what in the hell it was telling me. Oh well, yes everyone applaud, I;m an idiot and will be puting some clean oil in there tommorrow ha

 

Fine?

Not for long. I have heard of some manual tranny/t-case assemblies using ATF in the t-case (and considering the source, I'm not sure how accurate that was), but not for Toyotas. The ATF is only for auto tranny/t-case combos.

http://personal.utulsa.edu/~nathan-b...21lubrican.pdf

 

Dude, you're not an idiot. Self-negation is not necessary.

Now, where did you read that from and what transmission and transfer case do you have?

EDIT: Oh, the Haynes manual.....right. '90....V6. Transmission (edited) R150F?

 

2X me too

 

That really doesn't sound right. You might want to double check...

 

Some manual transmissions do actually recomend ATF. The m5od for one (used in explorer, ranger, and F-series)

Redline mt-90 works awesome. The trans will be happier with the gl-4, as the gl-5 stuff supposedly eats the syncros.

 

I don't think it "Eats" the synchros does it?

 

I believe it "reacts" to the brass syncros and there is some sort of chemical reaction..

 

Must be a pretty slow reaction. I'm pretty sure my truck had gl5 in it it's whole life before I bought it. (100,000miles). Synchros worked just fine. I started using gl4 but I think I put gl5 in last change because everyone seemed to be out of stock. 150,000miles now and still fine. I'll be going back to gl4 next change though. I did notice it shifted better with the gl4 so I guess there is definitely something to it.

 

it reacts and breaks down the yellow metals (brass in this case). something to do with the extreme pressure additives.

yeah, its hard to find gl-4 gear lubes at the store. I had shipped to me a couple bottles of mt-90 and it shifts a lot smoother, especially at lower temps, when the conventional oil was pretty thick.

 

Heh, I guess anything's possible

 

The FSM has the A340F as the ONLY transfer case that uses gear oil when behind a manual transmission, and only in automatic applications uses ATF.

http://personal.utulsa.edu/~nathan-b...21lubrican.pdf

The FSM says gl-4 or gl-5 actually. So, I don't think Toyota sees it as an issue of durability. I'm guessing, since it's been my experience, that it's because gl-4 works best but gl-5 is also acceptable.

http://personal.utulsa.edu/~nathan-b...21lubrican.pdf

I HIGHLY doubt it, if Toyota says it's fine, it's fine. Toyota knows exactly how to make things last a LONG time. It wouldn't make any sense for them to recommend it if it was detrimental to the transmission in any way.

See text above.

 

gl-5 is for hypoid gears, gl-4 for non-hypoid gears, and gl-5 is not considered backwards compatible to gl-4. If Toyota says you can use either, then that must be ok (I do not have my FSM on hand right now) but in my other cars that call for gl-4 it is not a good idea to use gl-5.

By the way, some E30 BMW 5spd transmissions allowed for the use of ATF fluid, so it is not unheard of. Again, since my FSM is not here by my side I have no idea what it recommends.