[DanaProsky]

Can anyone tell me the why there are 3 different codes for the automatic transmissions on 70-71 Challengers. D32, D34, and D36. Most tags I see have D32. The reference materials I have seen list D32 as a heavy duty automatic, D34 as light duty automatic, and D36 as A727 3 speed automatic. Whats the story?

[Moparman1972]

I would guess that the light duty auto is the 904 transmission. They're all 3 speed, i dont understand the D36 tab

[Thedeputy]

There's even one more code, D31. This is a small block 904.

Maybe the difference is in the application, like small block 727, big block 727 and hemi

Toon

[dave-r]

The transmissions were built to various specifications depending on what engine they were going to be bolted to. Differences to clutch pressure springs etc.
In other words the 904 and 727 had different levels of performance. The hemi 727 being the strongest with its max number of clutch springs and clutch plates in a larger front drum.

[DanaProsky]

The strongest transmission must be the D32 as I see that code on all Hemis, 440s, 383s, 340s, etc. I can not remember seeing D34s or D36s on a tag, although they are listed in reference books.

[dave-r]

I just gothome and looked this up.

The code changes from time to time so that is where some of the other codes come from. For example D34 would be in a 72 satellite with a 400 engine.

D32 was the code for all the Challenger big block 727s i think. From 69-71 i think. But there were still differences internally.