View Full Version : Trans Oil Thread

10-16-2005, 06:09 PM
This subject has been beaten to death on just about every Suby Forum and thats why this thread exists... I've read so many conflicting posts on gear oil for ours cars that I'm fairly baffled on what to buy.

-01 GT, manual trans
-44k miles
-no mods, daily driver
-light grind into 1st if you shift too quickly, and of course it will fight you into 1st if you're rolling at anything but a 2 mph crawl
-trans is a little stiff when cold but thats normal

Car has original trans oil now and I'd like to change it before winter rolls around. Ideally I want it to shift smoother into 1st gear (yes I know its a Suby thing to fight you into 1st), 5th is a hair notchier than other gears as well.

Examining the Redline Gear Oil line I think I've narrowed my choice down to 2:
75w90ns or superlight shockproof

Cobb Tuning has the following to say about the forementioned oils:

"75W90NS: Another GL-5+ oil which offers good lubrication and bearing life. Best for the rear diff but can be used in the transmission.

Shockproof: Expensive but a good oil for those who are abuse to the transmission/rear end and/or do quite a bit of racing. Use the SuperLight rated oil. Not a requirement for everyone but good stuff nonetheless."

info found here: http://www.cobbtuning.com/tech/gearoil/index.html

I've read some threads on Nasioc that make the 75w90ns sound like a cure-all and others that said it led to grinding; not much info on the shockproof. I wind the motor out often but never do I shift hard and it never has a problem synchronizing at high rpm.

I guess what I'd like to hear is what has worked for you? Any experience with the 75w90ns causing problems for members? Superlight Shockproof, anyone? I suppose I could go with an OEM oil, but what fun is that?!

My bad if this is the 10,983 time you've read a post like this. Before you type "search noob" remeber thats what inspired this thread in the first place.

10-16-2005, 06:13 PM
i have this same issue but have yet not found a way to beat it. as i'm sure it does for you, it worry's the bejeezus out of me of how much damage its doing to my synchros. sorry i can't offer any kind of help.

10-16-2005, 07:18 PM
Not many members here will tell you to "search noob". Most of us are here for questions and to ask questions. I haven't don't much research of late. I do have links (will post later time) that may answer some of your concerns. I was with my friend when he changed his tranny(auto) and gear oil. The results were better than I would have imagined. I figured it would just un smoother but not only that the car chirps tires in 2nd. I wouldn't do this before. He used Lucus synthetic tranny oil and 2 bottles of B&M "Trick shift" oild. He also used a Lucus gear oil but I don't remember the weight. I'm looking forward to my engine, tranny and gear oil change. New tires and intake with this colder weather I should feel something in the old butt dyno.

10-16-2005, 08:26 PM
so, which manual trans. fluid did you buy? does anyone have any recomendations? i have that same problem, and want to change the manual trans. fluid tom. when i had a dodge one time, if you changed the manual trans. fluid, and did not use a special kind of mopar manual trans.
fluid, it would grind when trying to shift? does anyone know if syncros in early 90's subies are known to go bad (like in hondas)??

10-17-2005, 11:45 AM
www.lersoc.com (http://www.lersoc.com) - the guys here run a blend of Redline oils. I think 4:1.
They also autox their cars, hard.

11-24-2005, 11:54 PM
I'd use Redline's Lightweight Shockproof.

We use it in every transmission we build. It's recomended by PPG, and it used religiously by our shop.

I'll be using it in my Forester, and in the dogbox going into my Legacy.