What's best for my trans?

[TurboDreamzGST]

So I picked up my 98 GST with around 85,000 miles on it and I want to change the gear oil because although it doesn't grind, it is a bit notchy and doesn't always just slide into gear, plus I want to keep up with proper maintenance in case the previous owner didn't. I'm just confused on what type of gear oil would be best for the FWD trans with this type of mileage because after searching, people say to use standand GL4 or GL5 75w-90, full synthetic GL4 or GL5 75w-90, syncromesh, and Redline MTF or MT-90. What would be best for my application?

 

[daren_p]

Redline MTL should be a good choice as it looks like your a stock/basically stock setup. This should offer good protection & should allow for nice shifting (unless your tranny has other issues).

 

[romeen]

I'm using a mix of 2/3 MT-90 and 1/3 MTL. My shifting has never been smoother.

 

[TurboDreamzGST]

Well I am on my way to my upgrade path currently running an evo 3 16g at 15 psi, type rs bov re-circulated, intake, Megan racing o2 housing, Megan down pipe and custom 3" cat bak exhaust and my next mods will be to my fuel system such as injectors and fuel pump ...is the red line MTF still my best choice? My final HP goal when I'm finished with the car will hopefully be in the 300-350 hp as my final goal.

 

[my dreamt dsm]

OP you can also try bg syncroshift at 48 buck for 3 quarts since ours only eats 2.8 quarts.

 

[TOONAH]

I put the cheapest gear oil I can find in my transmissions. OIL is Oil is oil. Save your money
and just use rated gear oil. That Redline oil does not do a thing for you. Chemicals known as "shift modifiers" are an illusion, a con job to get more of your money.
Remember those tired old Tide ads? New and improved! Yeah right. Oil is oil. End of rant!

 

[TurboDreamzGST]

Personally I don't agree with putting the cheapest stuff I can find in my trans..although I'm strapped for cash I would still spend the extra money for my gear oil since my trans is kinda important to me n it's not like I have to change my gear oil every 2500 miles like my motor oil

 

[Bluesideup]

I put the cheapest gear oil I can find in my transmissions. OIL is Oil is oil. Save your money
and just use rated gear oil. That Redline oil does not do a thing for you. Chemicals known as "shift modifiers" are an illusion, a con job to get more of your money.
Remember those tired old Tide ads? New and improved! Yeah right. Oil is oil. End of rant!

Tell that to Nissan. They filled the rear differentials of the first year Titans with conventional gear oil and within 15K most lunched the rear end. By switching to synthetic they have solved the problem.

I would agree with putting in MTL or a combination of MT90 with the MTL. I had great success with it in my GSX vs. the non-synthetic fill that was in it before. I am going to use the MT90/MTL combo in my Mirage trans when I get it swapped.

 

[TurboDreamzGST]

It be ok to just use straight redline MT-90 since it's equivalent to a synthetic 75w-90 which is what the owners manual calls for? And it's also thicker than the redline MTL and since I have higher mileage wouldn't a thicker oil like the MT-90 be better for protection?

 

[jholmes]

I'm using a mix of 2/3 MT-90 and 1/3 MTL. My shifting has never been smoother.

I'm generally not biased to a specific brand, but I've had the best of luck in my DSMs with this mix.

 

[TurboDreamzGST]

So will straight Redline MT-90 be ok?

 

[KFT0001]

It'll be fine. If you end up using something else, make sure it is a GL4 fluid. Do not use GL5 in the transmission.

 

[Hardin]

I use royal purple. It's pricey but for a good reason.

-Hardin

 

[Only2G4Me]

+1 for the BG Syncroshift. I use it in my transmission and have had great sucess with it. It also meets the specs for our trans. It is expensive if you buy it from the dealership but I believe you can get it online for cheaper. Road Race Engineering's Eclipse Synthetic Fliuds I think a few of the other supporting vendors sell it aswell. Syncroshift II is the synthetic stuff if that matters to you.

 

[daren_p]

Do not use BG Synchroshift unless your making stock like power. This fluid offers no wears near enough protection for more then stock torque levels. It may shift nice but when you take out your 3-4 slider, (which will result in much more damage) you may change your mind on fluid choice. Synchroshift is like water thin, if you are making stock power then it might be alright but most still recommend to change it like your oil if you are running it. For stock power & smaller bolt on's, I'd still just go MTL. For larger bolt ons I'd recommend MT-90.

Trans are not our cars strong point so defently a good idea to make sure your running the correct fluid (not all gear oils are not created equal, as mentioned above) & also to change it fairly regularly. I know TRE recommends like every 5K if your making some descent power.

To the OP MT-90 should be a good choice for you as it sounds like you do have some mods & are planning to make more power in the future.

 

[Mitchel63]

I use the OEM stuff for the EVO MR 6-speed. It was recommended to me by Jack McGee(Jack's trans). I have been using it for a couple years now and have been very happy with it!

 

[GimmeMoeBoost]

I put in about a 1/4 or so of lucas trans stabilizer in mine along with just the random ol valvoline or whatever the other brand was. Car has 100k miles and i believe the tranny was neglected, even by myself. The shifting was notchy, now its pretty smooth. I say just find a fluid you think is ok, or reccomended to be good and just try another fluid when you change the old fluid.

 

[Defiant]

F A Q

Pick ONE lubricant and use it. No additives, and NO MIXING.