Duramax Allison issue

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.

[ss3011]

Originally Posted by Ralph A Powell

Y

It's a Allison trans not a GM design and manufactured trans!

Allison was part of GM Hydramatic when the 1000 was developed . The Engineers from Indy work side by side with us in Ypsilanti . When GM went through bankruptcy Allison was spun off but the only Allison trans that remained with GM was the 1000 because it was in most of the 1-ton pickups . I think it's still built in Baltimore . Also Castrol developed the fully synthetic fluid Trans-Max , and later Allison re-named it Trans-Syn . It is a very good Automatic Transmission Fluid

[Mark Lewis]

Would the Trans Syn fluid be better in a 2001 1000 model Allison than the Dexron?

Originally Posted by Mark Lewis

Would the Trans Syn fluid be better in a 2001 1000 model Allison than the Dexron?

Yes! My 2003 has it. Smoother and less trans temp. Walmart is the best deal on approved Delvac Allison syn. I don’t use Castrol...

[monte385]

Originally Posted by Barry Polley

Yes! My 2003 has it. Smoother and less trans temp. Walmart is the best deal on approved Delvac Allison syn. I don’t use Castrol...

Summit's price was the best I found, never checked Wallmart.
Yes trans shifts smoother & runs cooler.

Works so well in the truck I’m tempted to try it in the race car.

[jmantle]

Originally Posted by Barry Polley

Works so well in the truck I’m tempted to try it in the race car.

I've used Transynd in Powerglides behind some big HP in an attempt to get better pump life when the pressure gets over 225 psi and it definitely seems to help. It is a full synthetic and a higher viscosity than regular Dex 3 fluid. Castrol was the original supplier when Allison wrote the specs for the fluid, TES-295. They have since added a few suppliers to the approved list. As far as what to use in an Allison, I wouldn't use anything that they haven't approved to TES-295.

Jim Mantle V/SA 6632

[Mike Rietow]

Allison part #. Change every other oil change. Deep pan and Transynd 30k. Transynd doubles the service life in conjunction with additional ATF (deep pan). Don't forget to take the magnet out of the old filter, to put in the new filter.