Duramax Allison issue

[Barry Polley]

Originally Posted by lorenr

I don't know much about the Duramax Allison, but I've needed to service both the Allison 3000 & Allison 4000.
When Allison switched from Dextron ATF type fluids to their Transynd fluid, I noticed the stuff is very thick and probably won't flow through most standard transmission filters.
Kind of an odd type fluid, but if you regularly maintain the 3000 & 4000, they are literally indestructible. Kind of need to do what they say.

Loren

Switching to the Transynd fluid or as I did Delvac approved fluid the transmission is smoother. If you tow heavy you might consider using the better syn fluid.