Best transmission fluid?

[Lenny5160]

Originally Posted by Jim Hawkins

This is what I use in the race car, service truck and the Duramax truck. A friend of mine works on Allison transmissions and says it is a extended interval oil, 200,000 miles. Works for me.

That's pretty much in line with the information I have found. It might not be 'better' than anything else under normal conditions and regular maintenance, but it will not break down under extreme heat and/or for a longer period of time than other fluids.

[jmantle]

Originally Posted by Lenny5160

I'm surprised to not see a mention of Allison TranSynd in this thread. It seems to be the "gold standard" in the bracket/Super-class world.

That's what I recommend for my customers that burn the paint off the torque converter, it does stand up to heat very well as most synthetics will. I've tried Transynd, type F, Dex 3, Dex 6, tractor fluid and see very little difference in performance. I'm now running Dexron ULV, it's a low viscosity fluid for the newer 8 and 10 speed and it does seem to be a little quicker. Less drag?