Transmission ID
Thread Starter
Instructor
Joined: Jan 2012
Posts: 215
Likes: 6
From: Mebane, NC
Transmission ID
I've been doing some research on rebuilding my muncie in a couple weeks. Someone previously ID the trans as coming out of a 69 truck. It is still in the car, PN is P8M17 cast into the housing. SN as near as I can read is: 18 (6 or 8) 400 (4 or A) 50. Is this an all syncro box? Will a rebuild kit from wilcox or Zip work? Does this trans have a drain plug? Some of the pictures in the workshop manual indicates it does not. I have some indication that the plug was sheared off, but it may just be painted over casting marks. Can't tell the exhaust pipe blocks the view. If no drain plug how is it drained? Perhaps though a lower shift cover bolt hole?
Burning Brakes
Joined: Dec 2010
Posts: 848
Likes: 60
From: CA
I'm going to have to guess at some of this (the VIN), but P8M17 is the date code. In this case it's a Muncie 4 speed transmission assembled on August 17th, 1967 and installed in a 1968 Chevelle that was built in Atlanta, GA. (Note that the transmission assembly date code is for the MODEL YEAR - 1968 - and not the year it was actually built - 1967)
As for the VIN, 18A indicates:
1 - Chevrolet Motor Division
8 - Model year (1968)
A - Assembly plant (Atlanta, GA)
The rest is the partial VIN of the car it came out of but it should be 100xxx since the Chevelle production started at 100001.
If there's no drain plug, it's an M20 or an M21. Only M22's had drain plugs in 1968. To drain an M20 or M21, you can either remove the transmission and drain it that way, or use a pump to remove the oil from the fill plug. Either way, let the guy that's rebuilding it worry about this.
Ed
As for the VIN, 18A indicates:
1 - Chevrolet Motor Division
8 - Model year (1968)
A - Assembly plant (Atlanta, GA)
The rest is the partial VIN of the car it came out of but it should be 100xxx since the Chevelle production started at 100001.
If there's no drain plug, it's an M20 or an M21. Only M22's had drain plugs in 1968. To drain an M20 or M21, you can either remove the transmission and drain it that way, or use a pump to remove the oil from the fill plug. Either way, let the guy that's rebuilding it worry about this.
Ed
Thread Starter
Instructor
Joined: Jan 2012
Posts: 215
Likes: 6
From: Mebane, NC
Thanks
I'm the one rebuilding....will find out when I get it out. Need to finish reinstalling the rear crossmember isolation mounts before I tackle the trans. Trying to keep it at one project at a time.
