Atf 03 duramax 2500

[pjc360]

My mother in law has a 2003 chevy duramax, it has 160 thousand miles on it. Yesterday she asked. E to pick up a camper for her, so I did and I had to drive 60 miles to the next town to pick it up, half way home pulling the camper I fel the transmission slip a little bit. And I had the tow haul button on which keeps it from shifting into overdrive.
I oulled over imidiatley and checked the fluid and it was full and it didn't smell burnt to me.
So I let it sit there for about 10 to 15 min idling to give the transmission a little break.
Then I took back off and it was fine and I didn't feel anymore slipping. When I got home I told her I highly recomend she service that transmission with a new filter and fluid.
Of course she asked me to do it and I agreed, I'm thinking about putting dexron vi in it for her cause she hauls a 5th wheel horse trailer around all year long and she takes the 5th wheel out of town on 500 plus mile round trips.
I told her I would service it with dexron vi which is a better fluid and then in about 2 to 3 thousand miles I'll need to drain the pan again and re-fill with dexron vi to get most of the old fluid out and get new fluid in it.
Is dexron vi fine for this transmission? I don't see why it wouldn't be since its backward compatible to dexron 3.

 

[stockrex]

what do you have in it? Alison?

 

[SwampSurvivor]

That's just asking for you to be blamed for the transmission failure ...

 

[InhalingBullets]

Originally Posted By: Miller88
That's just asking for you to be blamed for the transmission failure ...


Its his mother in law...who do you think is gonna get blamed anyway?

 

[TiredTrucker]

The Allison? That requires TES-295 fluid doesn't it?

 

[901Memphis]

Isn't that a real Allison that should have something like Castrol transynd?

Amsoil torque drive is also appropriate here.

 

[901Memphis]

Also here's a good read if you have time to look through this thread.

https://bobistheoilguy.com/forums/ubbthreads.php/topics/3279587/Former_Allison_Transmission_Fl

 

[dlundblad]

Originally Posted By: Miller88
That's just asking for you to be blamed for the transmission failure ...


x2. Oil changes and tire changes are the limit for me unless they ask for my help.

 

[29662]

According to TSB 04-07-30-037c Dex VI is the recommended fluid for that transmission. Just remember no good deed goes unpunished.

 

[Bandito440]

If that transmission fails after you change the fluid, it's going to be your fault. Keep that in mind.

 

[clinebarger]

If it really did slip, The TCM would immediately go into Limp Mode. You may not be used to how Allison 1000's behave?

Their are several cases of pump/converter seals leaking after using Dexron VI in 5-speed 1000's.

I would use a Allison approved ATF.

 

[pjc360]

It is an Alison transmission but I think it's only a 4 speed Alison. Ether way it's an earlier Alison transmission since its in a 2003. I guess if I end up doing it for her I'll use the transyd since its Alison approved.

 

[Whitewolf]

I suggest that, to be completely safe, you just see what fluid is recommended in the vehicle manual and use that. If anything goes wrong afterwards you can't be blamed.