2001 Allison 5-spd Auto maintenance question

[biketopia]

I know this is a two week late response, but when I had my 03 duramax I would do the external filter every 10k, drain and fill the pan every 25k, why my truck was used it was used hard. At the time, all the Allison documents I had and speaking with the Allison dealers they all said the internal filter should only be replaced at a rebuild. I did mine at 100k just for the hell of it but then was doing regular drain and fills with the external filter and never thought twice about dropping the pan again. Use the correct TES 295 approved fluid! Unless your trans has been built, then some builders recommend a Dex3, otherwise stick with approved fluid. Also make sure you remember the magnet, when I did the first external filter when I got my truck with 72k on it the magnet was gone...

[hatzie]

Originally Posted by biketopia

I know this is a two week late response, but when I had my 03 duramax I would do the external filter every 10k, drain and fill the pan every 25k, why my truck was used it was used hard. At the time, all the Allison documents I had and speaking with the Allison dealers they all said the internal filter should only be replaced at a rebuild. I did mine at 100k just for the hell of it but then was doing regular drain and fills with the external filter and never thought twice about dropping the pan again. Use the correct TES 295 approved fluid! Unless your trans has been built, then some builders recommend a Dex3, otherwise stick with approved fluid. Also make sure you remember the magnet, when I did the first external filter when I got my truck with 72k on it the magnet was gone...

It came off the line with GM Dexron III in it.
The 2006 trucks came off the line with Dexron VI in them.

Apparently GM recommends Allison Transynd TES 295 for temps below -40° ambient so it does work and it won't hurt the Allison 1000 to run it if you can handle the price.

The below dieselplace thread recommends the TES 295 rather than Dexron VI

TES 389 is supposed to be exactly the same as the old Dexron III H. Chevron makes it as ATF HD 389.

There's a bunch of Dexron VI might do this or that bad thing in this thread. It might, but GM used it and I can't find a TSB warning to not use Dex VI so I'd want to do a bit more research before I take somebody's word for it.
https://www.dieselplace.com/threads/...ansynd.318081/

More arguments on BITOG. https://bobistheoilguy.com/forums/th...dex-vi.159697/

Kinda like the religious wars over "my engine oil is better".

If it was my truck I'd run the Dexron VI in it, change the spin-on filter every other engine oil change, and change the fluid at 2x the spin on filter interval and not worry about it.