[Yotaguy3.4]

This weekend I was finally able to cross some things off the maintenance list. I replaced the gear oil in the transfer case & rear diff, cleaned and oiled my K&N air filter, and gave the throttle body a much needed cleaning. Next will be the transmission fluid and then move on to rebuilding the suspension components. Any suggestions on what trans. fluid to use? I used Valvoline for the t case and rear diff.. Been hearing a lot of guys talking about Redline MT-90 for manual trans.. anybody else been doing lots of maintenance lately???

 

[Cusser]

I would use the same 80W-90 gear oil in that manual transmission that you used for the differential.

I have 5 manual transmission vehicles, that's what I use, 80W-90 gear oil .

 

[shakedownstreet]

Just make damn sure you get GL4 grade trans oil. GL5 will destroy it. A lot of people use AMSOil.com

 

[Cusser]

Just make damn sure you get GL4 grade trans oil. GL5 will destroy it. A lot of people use AMSOil.com

I'm pretty sure I have used GL5 gear oil in my 1998 Frontier since we bought it in 2004. That was 160K miles ago.

An API GL-4 gear oil has about ½ of the level of sulfur/phosphorous additive that would be in the API GL-5 product.

 

[shakedownstreet]

I wouldn't risk it personally. The manual says GL4 so that's what I would use. Doesn't mean I am right

 

[Yotaguy3.4]

Yeah it’s a little confusing for the trans.. the manual was pretty clear on the other fluids (80W-90 for the diff, 75W-90 for t case), and it does recommend 75W-90 API GL-4 for the trans.. However I’ve read the back of a few different gear oils that have said they are compatible with manual transmissions that require GL-4 and/or GL-5...