GM Synchromesh, which one?

[Pete Munroe]

Gang,

Changing the fluid in my TremecTKO.

Went by the GM dealer and got three quarts of:
-GM Synchromesh Trans Fluid "FRICTION MODIFIED" #12377916

went home and looked at the OLD bottle of GM fluid:
-GM Synchromesh Trans Fluid #123455349

The TREMEC manual specifies the standard fluid #123455349 for the TKO, not the "Friction Modified". I am guessing the "Friction Modified" fluid is too slippery to drive the synchros in this ...or is the other way around?

Anyone know the specific application of the "Friction Modified" and what the characteristics of the fluid are? More or less slippery?

Thanks,

Pete

[mikeforte]

Hi Pete,
The GM# 12345349 is the correct number. Just return the ones you have for the correct lubricant.

[Pete Munroe]

Mike,

Thanks for the guidance...I will take it back and hopefully they have the correct fluid...local Chevy was out, sent me to the Cadillac dealer. They had this stuff but the parts guy at either place didn't know anything about it much less for a "Tremec TKO"...

Just out of curiousity is the "Friction Modifier" flluid more or less slippery? and which trans if it intended for?

Thinking about limited slip diffs, where the "friction modifier" or additive, as I understand it, increases friction so the clutches don't slip...different design synchros may need more or less friction...so which way does the modifier take the fluid?

Thanks,

Pete

[Rick Parker]

Suffice to say if you found it at the Cad dealer that it was intended for the CTS V which is quite a ride in its own right. I think some of them had Gertag transmissions.

[madmaxx]

Much Kudo's to YOU!!!!! Excellent job researching and not creating a problem. Most would have relied on the dumbsheet behind the counter for advice and dumped in the transmission.

[flipscobra]

It certainly is not cheap, 3 quarts cost me about 55.00$. the part stores carry syncromesh by Pennzoil, its about half the cost of GM. Flip

[DanMartin]

http://www.pennzoil.com/documents/Sy...ns%20Fluid.pdf

The Pennzoil stuff is direct replacement for the GM fluid, per that data sheet....

[Tony Ripepi]

I switched to the Redline equivalent after running the GM for ten years/18000 miles and it is much smoother.

TR