Transmission Identification

[juiceman650]

Hey guys, I'm tryng to ID the transmission in my truck in case I think about messing with it. I checked the sticker in the glovebox and its says M40 fro the transmission. Its a 75 Chevy C10. Im a little confused because I usually hear that these trucks either have a TH350, TH400, or TH700R4 but mine just says M40..any idea what that is? I googled it and it comes up as a Camaro tranny.

[bikes&bowties]

Look at the pan.. You can find identification charts online...

4 speed- deffinitely a 700r4

Square pan 3 speed- th350

Irregular shaped pan 3 speed- th400
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[juiceman650]

Originally Posted by bikes&bowties

Look at the pan.. You can find identification charts online...

4 speed- deffinitely a 700r4

Square pan 3 speed- th350

Irregular shaped pan 3 speed- th400
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thanks a lot man, will check in the morning though

[bikes&bowties]

The th350 isn't perfectly square but damn close..
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[hatzie]

The RPO M40 on your SPID is for a TH400.
If your SPID tag said M38 it would be a TH350.
The 4L60/TH700R4 was not available in 1975 but the RPO is MD8.

Your truck is 36 years old so anything could be installed now.

chevy-transmission-identification

[rwhit57]

the 400 had an electronic kick down switch, and the 350 has a cable. This is another way to check.

[juiceman650]

Alright, thanks a lot guys. And hatzie, you are correct about the new parts. The sheet in the glove box said it was a step side bed, but it has a fleetside short bed on it. Thanks for the info fellas
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