[Pooch2]

Transynd or DexIV? I'm confused on which one to use, thanks in advance.

 

[Piper One]

Transynd. 295 or 668, doesn't matter, but Transynd over Dex6 everyday.

 

[The_G]

I have the same question, new to me, 2011 Chevy 2500HD. Likely due for a transmission flush. Unsure if it ever been done, I'll have to go through the service records that came with the truck. Sounds like the Transynd is the way to go. But if there's Dexos in it can they be mixed? If I decide to go with the Transynd?

 

[Piper One]

They will mix fine. No flush required (and not Allison recommend either). Change it, drive it for a bit, change it again. Allison considers that good enough for extended warranty in applications they provide warranty (non pickup application). If you want to get super picky, look up the Hoot method, not required but it is more complete (and more work, fluid). When I switched over I just did the double drain, that was ~200k ago in 2008.

 

[BoiseRob]

The best fluid for a stock trans is Mobil Delvac ATF...

On/off highway - Mobil Delvac 1 ATF | Mobil™

Mobil Delvac 1 ATF is a fully synthetic fluid recommended by Allison Transmission, Inc. approved against the Allison TES-295 Specification.

www.mobil.com

 

[SuperBlackTruck]

I went with BP autotran which meets the TES-295 which I found at the local NAPA, next trip up north I might stop at merchant automotive.

 

[DonkeyDiesel]

And don’t flush, just change or HOOT

 

[sambor]

Delvac comes in the 668 as well