My 1969 Corvette Project

The Saga Continues

March 3, 2001

It was still pretty cold, so I decided to do some bench work, up away from the cold floor. I decided to stick with the original Muncie transmission, so I ordered a rebuild kit, and got started.

The code P9C22A identify this as an M20 transmission assembled on March 22, 1996. The two grooves cut into the input shaft, and the number of splines back up the ID.

March 19, 2001

I first removed the cover, cleaned it, and rebuilt it with new seals.

Here is the clean rebuilt assembly. Either this transmission was rebuilt before, or the over 80,000 miles on this car were fairly easy, because the wear was minimal.

March 20, 2001

A special tool (flat wrench) was supposed to be used to remove the retaining nut in front of the bearing, but the rebuild kit came with a new one, so I ground the flange off to reveal the flats, and used a standard wrench to remove it.

The extension came apart easier than most parts of the car. This unit was in really good shape. If I had know, I would not have rebuilt it. Either someone had rebuilt it, or babied the drivetrain.

After further disassembly. It looks like a mess, but it is really not that bad, since I documented it well, and have the proper manuals.

I did some further disassembly, and cleaned up the parts.

I had reservations about replacing the rear bearing, because it was so thin, but it was pretty scratched up. Here is the before and after.

I made an insertion tool by cutting and grinding a piece of pipe. I then slid it onto the output yoke, and used the yoke shaft as a guide.

This magnet glued to the bottom of the transmission is a good trick, but I don't think the factory did this. Another indicator of a rebuild. There was a lot of metal stuck to it, so I know it works.

The main shaft was assembled.

The countershaft was assembled. There were a lot of bearings in there. It really helped to have the old shaft to use to get everything set up before the new shaft was inserted.

The snap rings were the toughest I have ever encountered. I used a standard snap-ring pliers, but highly recommend a heavy duty snap-ring pliers.

A new backup light switch was $55, so I decided to rebuild it. It took a couple of hours. I had to get a new tiny o-ring into the shaft bore of the switch, but that was the toughest part. It turned out good. I sealed the cover with the same rubber coating that I used on the battery cable clamps.

Here is the finished transmission.

Because of the rear-end ratio change, I had to install a different speedometer gear. The green one is the new one. I went from 19 to 22 teeth.