Dex 6 transmission fluid

falconbrother wrote:
A couple of years ago I pulled the transmission pan and replaced the filter. Since then I have done a few drain and fills of the fluid. .

You putting on some real high miles? 2 years ago givertake, you changed half the fluid (pan drop gets about half) and you've changed half the fluid again 3 times since?

The most stringent requirement I can think of puts you well over 100k miles since the filter change.

And I'd use AmZoil!
lol

^ What makes you think it's an Allison trans?

Actually based on the OP's post it's almost certainly not, since the "filter" is external on an Alli (yes I know there's an internal filter, but it's really just a screen. A chunks catcher.

Well, for starters what vehicle are we talking about? I did a lot of research lately for the Allison transmission in my 2005 Chevy. As it turns out when GM switched from Dex3 to Dex6 they didn't realize that the Dex6 hardened the seals in the Allison and made them leak. They eventually discovered this and updated the seals but some trucks with the old style seals still left the factory requiring Dex6. Your not supposed to put Dex6 in an Allison older then about mid year 2006 or it will harden the seals. The go-to transmission fluid now for the Allison is Transynd which is a synthetic engineered by Castrol specifically for the Allison. If you buy GM fluid for the Allison now days it is supposedly rebranded Transynd. It may be a great fluid for your transmission instead of the generic Dex6 but I have no idea.

If it didn't eat up seals in the Ford, why would it eat up seals in a Chevy? It probably had more to do with viscosity used back then. I doubt any transmission fluid today would eat metals we have now.