[muddinmachine]

Sorry if this sounds like a dumb question, but with the older gas motors, you had tranny combos of the TH350, TH400 and the 700r4. Are there different model Allison Trannys that come with most Duramax diesels, or is the allison just one type?

Thanks

Nick

 

[Iron Horse]

there are two types

5 speed auto, whichj is 01-05 and the 6 speed auto which is 06+. They are both nearly identical, the 6 speed has dfferint prgramming and some added cooling passages. Both have the same case and gearset, but the 6 speed engages differnt planataries to get the 6th gear.

 

[DIXIEDIRT]

they have an extra hole in the throttle body to engage the 6th gear planetary