Saturn Manual Transmission "No Service Required"

[actionstan]

Hello All,

I have a 1999 Saturn SL1 with 130,000 miles on the clock. The service manual states the first fill should have been changed out at 6000 miles, then never again.. while I understand a M/T isn't as hard on ATF as a A/T, would it be a bad idea to change it out as preventative maintenance, I dont know when.. if ever the last time it was changed.

I was wanting to use Mobil 1 synthetic ATF as the fill, but I have heard rumors it may be to "Slippery" for the old syncros, and cause them not to work, or that it could leak out of the transmission and get on the clutch and ruin that. I even went as far to email Mobil, but I believe they had a misunderstanding, as they said not to use synthetic in a older transmission as it may dislodge dirt, and clog the transmission(I don't think they paid attention to the part about it being a M/T.)

Is any of this warranted? Could using synthetic ATF in a older MT cause any issues? I have also considered running regular Valvoline or Pennzoil ATF for a short fill then going to mobil1 ATF, Maybe this is a better idea? Maybe I should leave it alone all together?

Let me know your thoughts! Thanks!

 

[dparm]

From what I see, any Dexron-III is fine.

 

[millerbl00]

I would go ahead and change it with the correct fluid.

 

[tommygunn]

Changing it will not hurt anything, even when using synthetic.

However, do not use Dexron-VI: it is not backwards-compatible with manual transmissions.

The factory fill was most likely not synthetic anyway, nor was the fluid put in at the 8kmark. You do not need to do a short interval with regular ATF. You can use M1 right away.

 

[JethroBodine]

Mobil1 ATF will do fine. Castrol Dex/Merc is another good choice.

 

[Rat407]

I changed out the ATF in a 94 Saturn manual transmission that had 140k on it and all has been well. No issues and I even installed AMSOIL's ATF.

 

[default]

Pennzoil synchromesh will work too.

 

[MolaKule]

Or any of these:

Quote:
B. The next higher viscosity MTL would be the 7.5 cSt versions (About the same viscosity as a DexronIII)

1. Royal Purple's Synchromax

2. Ravenol MTF-2

3. Honda MTF

4. VW part number G052512A2

5. GM Manual Transmission and Transfer Case Fluid

6. BMW (Pentosin) MTF-LT-1, 2


C. The next higher viscosity MTL would be Castrol Syntrans V FE 75W-80 8.0cSt

D. The next higher viscosity MTL would be BG Synchroshift II 8.2 cSt

E. The next higher viscosity is Mopar Type MS-9417 MTL 9.0cSt

F. The next higher viscosity MTL would be Pennzoil Synchromesh 9.3 cSt


Technology of Manual Transmissions and Fluids