[kcmusa]

is it OK to mix whats in there from stock (2015) with TES-295 syn by just draining and refilling.

 

[Hook'em_Horns!]

Compatible, yes.

 

[Dirtymax66!]

change out external oil filter , allison genuine filters are best and then dump and refill with mobil one atf tes 295 compatible. two gallons are more then enough for just that. no need to change the internal filter till you rebuild the trans

 

[mwswarrior]

I used transynd, a deep Allison pan and Allison Filters. Easy, simple, done. If you would like a bit more performance, look at Transgo Jr. Kit.

 

[Dirtymax66!]

i used mobil delvec 1, its tes 295 approved and good for the 25000 mi interval and cheap on summit racing. i replaced my external filter with a allison spin on and left the internal filter alone since it gets changed only when rebuilt

 

[LMLLover]

You left in a 14 year old transmission filter? Brilliant !

 

[elkhornsun]

Hey guys, so i recently bought my truck and am now looking into doing a service on the transmission. So, i did a bunch of research and now am worse off than if i did not look into it. So, what do you guys use for ATF fluid? do you guys take the pan off to clean it out? Use the OE Filter or a aftermarket? I am leaning towards Amsoil ATF or their Torque Drive ATF, anyone have any experiences?

I use Castrol TranSynd which is an Allison approved TES 295 ATF. It is good for 150,000 miles or 4,000 hours or 48 months as compared to the TES 389 ATF at the Chevy dealer which is good for 50,000 miles or 2,000 hours or 24 months. My local Allison shop has the TranSynd which is what they use for all commercial vehicles. Cost for the ATF change at the Allison dealer costs less than the change at the Chevy dealers with the inferior ATF.

I would avoid ATF that is not approved by Allison with their testing. Amsoil would be a poor choice for anything considering how poorly their motor oil additive mix is for diesel engines.