2004 Z06 Manual Transmission Fluid

vetteracer11 · 12-16-03, 04:15 PM

I just purchased a 2004 Corvette Z06. I currently have 538 miles on the car. I want to replace the T56 manual transmission fluid, which I know is just regular Dexron III Automatic Transmission Fluid, with a Fully Synthetic ATF fluid such as Mobil 1 ATF. I have always used the Mobil 1 ATF in my previous Corvette, 1994 with the Automatic Transmission. The synthetic ATF flows much better in the cold weather and I know that the synthetic holds up much better in the higher temperatures. I autocrossed my 1994 Corvette quite a bit & I NEVER had any tranny problems because I always used the Mobil 1 synthetic ATF and changed the fluid and filter twice per year. I want to use the best fluid that I can in my new 2004 Z06 and I am also expecting the Mobil 1 synthetic ATF to help improve the shifting effort when the weather is cold and also to hold up better in the high temps of autocross racing. I have read many conflicting comments on the Corvette forums regarding Synthetic ATF and the T56 tranny of the Corvette Z06. Some say that the synthetic is great; others say that it causes problems with the synchros and blocking rings because the synthetic is too "slippery".

What ATF fluid do you recommend as the BEST Dexron III fluid to use in my new 2004 Corvette Z06. I would definitely prefer to use a 100% synthetic ATF fluid, such as the Mobil 1 ATF or the Redline D4 Synthetic ATF.

Thank you very much for all of your help with this.

Also, what is recommended as a fluid change interval?? Once I know what fluid you folks recommend, I plan to change the T56 tranny fluid twice per year, irregardless of how many miles I put on the car, because I will be autocross racing the car during the summer and then driving it in the cold weather also. If a 100% synthetic ATF is recommended, I plan to replace the regular Dexron III fluid at the first engine oil & filter change which I plan on doing at 600 miles. This way the car gets synthetic ATF fluid pretty much from the very beginning of its life.

Thanks,

Mike