I've searched and found that GL-4 gear oil should be used in my transmission and everyone seems to be using redline oil for their transmissions. But I can't find any gear oil that is only GL-4. My question is can I use Valvoline 80w-90 gear oil even though on the back of the bottle it says, "Recommended for all hypoid differentials (conventional and limited slip) and manual transmissions where an API GL-4, GL-5 or MT-1 fluid is specified."

Yes you can use it. I like the synthetics a little better. As long as any of them meet API GL-4 your good to go.

FWIW,

Carl B.

I have tried Redline oil & Nissan oil. I end up going to Nissan dealer to get some oil supply for my cars. Mitsubishi is also carrying GL-4 trans oil for their car.

I like Redline MT-90 for my tranny. Shifting was smoother than with dino-juice.

Didn't see any redline at the local O'reillys or Autozone. What you guys think about Royal purple?

Royal purple is fine - I've ran it in a couple of Type B's - one 4 spd and one 5spd. Both were good transmissions with no shifting or synchro problems to begin with.

FWIW,

Carl B.

Alright, cool. Appreciate all the help.

There is a little confusion here because oils that meet GL-5 supposedly eat yellow metal. I did a little searching on this about a year ago and it looks like there are either NO or VERY FEW oils that are GL-5 rated that still have this problem, and if memory serves any oil that is also rated GL-4 or MT-1 is good to go. I like SWEPCO 201, and I used to cut it 50/50 with ATF to make it a little thinner and get a faster shift. Works great in Nissan transmissions either way, and I use it straight in Nissan limited slips, no LSD additive required. Lots of people like Synchromesh, which is available through Pennzoil and a couple other distributors, and I think you can get it at GM dealers as well. Really though any good quality gear oil will do.