2008 Corvette M.T. lube requirement

[Pablo]

Does anyone know what GM is now saying for 2008 6 speed manual?

I read at first it was Dexron VI.....don't know if that's factual. Then GM called out either Dexron III or a GM manual trans lube (that is some modified Dexron III ATF).....

Amsoil guide says:

Quote:
1. Gm recommends part no (USA 88861800) Canada (88861801)
or equivalant for manual transmission, transfer
case applications.


Which I don't know what that part # is.

Amsoil recommends: ATF or ATD.

Thanks,

Paul

 

[cosynthetics]

Pablo

The owners manual says the same thing...

Manual
Transmission
Manual Transmission Fluid (GM Part
No. U.S. 88861800, in
Canada 88861801).

Not sure how to get more info.

 

[XS650]

Back in 2006 some GM source erroneously said DEX VI for the Corvette Tremex manuel tranmissions. Then they corrected that and changed it to the GM P/N fluids.

IIRC, they did that because GM no longer officially recognize/validates DEXIII which is what the transmissions were designed around.

 

[Pablo]

I don't recommend Amsoil ATF for that reason.

ATD is HD and has a vis of 7.5 so it works fine.

Need to get a fix on 88861800. If it's just Dexron III - what keeps is from shearing back to less that Dex VI territory?

 

[The Critic]

Originally Posted By: Pablo
Need to get a fix on 88861800. If it's just Dexron III - what keeps is from shearing back to less that Dex VI territory?

GM may purchase manual transmissions from other sources. If the transmission was originally validated with Dexron-III, it may not be worth the $$$ to revalidate with Dexron-VI

 

[Pablo]

I don't think GM is that sloppy - or they do they not care about shift feel?

Standard Dex III (yeah I know, no such animal) shears like a banshee.....to 5-6 cSt land in a MT, especially in a driven Corvette. People are reporting less than optimum shifting with FF.

I was hoping Whitewolf could fill us in.

 

[artificialist]

TranSynd fluids are more shear stable than Dexron III, and have the same starting viscosity and frictional properties.

Castrol TranSynd or Amsoil Torque Drive ought to solve the problem.

 

[Pablo]

Originally Posted By: artificialist
TranSynd fluids are more shear stable than Dexron III, and have the same starting viscosity and frictional properties.

Castrol TranSynd or Amsoil Torque Drive ought to solve the problem.


That good sir is my EXACT recommendation to customers. People are a bit resistant though (even though it's even on the Amsoil recommended list, not just ME). Amsoil ATD has a 100°C vis of 7.4 cst, a great gear protecting additive package, good temperature behavior (even very cold)....

 

[bdcardinal]

iirc the trans in newer vettes is sourced from Tremec. you could always inquire with them as to what they recommend.