Saturn Fluid 21018899 for GM Getrag Manual Trans

[JohnBrowning]

I have used Redline for years in Domestics and Imports. I am useing MTL in my Toyota 5 speed Camry and loving it especialy during the winters cold shifting is the best. I was one of the first people to bring the 50/50 MTL/MT90 mix to the Corvette clubs. I grew up tunning Imports and worked as a Mechanic in Germany and then in the USA before going back to college. I was big into MR2's and found that Redline MTL/MT90 worked great in them as they had notchy shifting and power shifting was almost impossable unless you had pop eye forarms unless you ran Redline. So when I started to work at GM with a lot of executives and the CHildress Racing I tossed out Redline 50/50 for a friend at work and it exploded like wild fire!

So I would start with 100% Redline MTL first if you need to thicken it then latter on you can add some MT90. MTL is thicker then ATF but drasticly thinner then 70W90 gear oil. The MT90 is the same formula basicly as MTL only it has the same viscosity as a 70W90 Gear oil.The chemistry though between them is the same.Ihave never found anything better then Redline MTL,MT90 or some mix of the two of them! I have not tried Amsoils latest stuff so I cannot coment but I can coment on Redline performing much better as in 3X better then Royal Purples Synchrmesh,GM Synchromesh,Texaco Synchromessor Pennzoil Synchromesh!

 

[Audi Junkie]

Thanks John. The Syncromesh thing is finally sinking in. MTL (afik) is the midweight option, equivalent to Syncromesh viscs at 10cSt. When I say midweight, I mean heavier than ATF, but lighter than 90 weight gear oil.

What confused me about Syncromesh is that it appeared to be specificly for trans that take motoroil, but it was formulated more like manual trans fluid. This seemed to exclude trans that take ATF (or 90 gear oil), now I realize this is not true, you can mix and mstch for your needs. I never had a trans that took motoroil exept an old Saab, but I always fantisized about using GC in a trans. I used MTL in my Acura at 5000 miles, it's what the Asian mfg's spec as a 80 or 85 weight, a "Syncromesh" visc, correct me if I'm wrong. What I don't understand is why GM did not spec their "fine" Syncromesh for this trans, mpg?

I understand too, that going thinner is a bad idea, but a lot of guys use the 50/50% Redline mix in Audis for cold climates. It makes sense for shifting but also most owners in USA do not heat up the box as much as the Euro mfg recommends (75w-90). I will be asking for guys to let me know if they can take some IR temp readings.

Anyway, in our app, it takes light ATF, but I wolrry about wear and a "loose box" from lugging. We also take short trips and live in a cold climate. Also we are blasting along w/ only 140 hp. So, a mid-weight gear oil is ideal. Silkolene SRG Pro 75 is the right visc and a ~super~ high end formula. It is recommened on the UK Astra forums by tuner shops and oil retailers (a common enterprise over there).

So, it's done, I ordered SRG Pro 75, at least one litre really cheap on EBay. I'll see if their price holds up, it's $23 at silkolenestore.com, that's not too good.

I won't be putting it in until next spring/summer. Some oem recommendations for this trans say to change oil once, at 6000 miles, So I'll wait a while.

Thanks for the feedback.

 

[Bluestream]

Originally Posted By: Pablo
Bluestream - if you want to take a small step up in viscosity and get manual gear box type protection, you can try Amsoil MTF.

Amsoil MTF link


FWIW, I bought 3 quarts of Amsoil MTF, and plan to overfill to 2.6 quarts. I will let you know if I notice any differnece when I get in installed.

 

[Bluestream]

I thought I should at least update this old thread, after all it now has 3200+ views. I drained out the Saturn fluid that the dealer had installed, and it came out very clean and red in color like ATF. It seemed thicker than ATF, and it also had a bit of a sulphur smell, so I think it might be a GL-4 fluid. It looked so clean, I thought I had wasted my money buying the Amsoil. However,After driving the car around, the shifting was noticeably improved, so changing the fluid was worthwhile. I used Amsoil synchromesh, and recommend it for this application. I overfilled the transmission as the previous TSB suggested.