Transmission Identification!
 

I've got a 57 Chevy 3600 with a 235 I6 from a newer vehicle, and a transmission i'm not convinced is original.

It's a 4-speed, with the ratcheting squeeze-brake on the output. On the top of the driver's side, it says GM2 591568. On the passenger side, it says J1955.

I'd like to get a gasket set for this, and I need some parts for the shift handle where it enters the transmission, or a new shift handle. I can't seem to find enough information to know what to get.

Please Help!

Thanks

Re: Transmission Identification!
 

The part number you have is for the shift housing, the main case should have another number. The date code is September (J) 19th, 55 or 65, usually there are only three numbers. That tranny was the main stay 4 speed from 47 to early 70's. Early models had 4.6" input bearing retained, later 5.125" retainers. I think the input shafts were different sizes too. I thing the shifters are all the same. Let me quess that the tabs on the cone that hold the shifter in place are broken?? Common problem. You can still probably go to the Chevy dealer and get the gasket set since it is so common. They will take a lot of abuse, I had one in my 59 that was growling when I put it in and growled for 10 years, about 40K miles but never broke.

Re: Transmission Identification!
 

Thanks for getting back to me. What broke is the cylinder that houses the metal tab that moves the gears. The roll pin is WAY worn out too. it's functional, but VERY sloppy, and i fear may brake more. I ended up making the gaskets from a gasket material I had. Hopefully they hold up. Would I put 80/90 Gear Lube in there? or ATF? I was guessing gear lube.

Re: Transmission Identification!
 

80-90W should remove the heat,
You could use RTV for gaskets in a pinch if you let it set up a bit, works good on the rear end cover also!

Re: Transmission Identification!
 

i think those are the sm420 but i may be wrong

Re: Transmission Identification!
 

Looks like it could be a Muncie SM420, from what i'm finding on the internet. Thanks!

Re: Transmission Identification!
 

Here's a pic of several