Saturday, September 09, 2006

The Adaptor Plate: A Necessary Evil

The adaptor plate is the piece that connects the motor to the transmission. It consists of three parts: the aluminum transmission profile plate, which is cut and drilled to bolt onto the transmission and replicate the original mounting surface of the engine; the steel hub, which attaches the motor output shaft to the flywheel; and the aluminum motor ring, which acts as a spacer between the motor and the transmission to keep the correct spacing for the clutch. Several small spacers between the motor and profile plate are sometimes used instead of the motor ring.

I now have to decide if I want to get the adaptor plate made at a local machine shop or if I want to get it made by a specialized company out in California. I was originally thinking that I would just get it made in CA. They have a library of patterns for various cars and motors, and at the time I thought they had a pattern for my truck on file. The catch: if they don't have a pattern for your vehicle, you have to ship your transmission out to CA and get it measured.

The problem arose when I realized that my truck didn't have the original engine and transmission in it. When I went to get a distributor cap and rotor for it (back in the day when it still had an engine), I just got one for an '88 B2200. I mean, duh, that's what kind of truck I have. When I came back with the cap, it didn't fit. That's when things started to get fun. It turns out that the original distributor cap was off of a 2.0 Mazda, not a 2.2. I then noticed a whole bunch of pinched off hoses and unplugged connectors. And then, as I was removing the transmission, I noticed that the crossmember had moved forward to accommodate a new transmission. I just assumed that it was out of a B2000, because of the distributor cap. The company out in CA had a pattern for this transmission, so I was golden. For a little while, anyway.

Fortunately, I got in touch with another EV guy who is in the process of converting a B2000, and he sent me a pic of the bell housing on his truck. Mine looks nothing like it. Oh well, back to the drawing board. I'm going to see if the auto parts store can run the numbers for the transmission so I can find out what it is.

Having actually seen the clutch assembly and how and what it bolts to, I'm now thinking that it wouldn't be prohibitively difficult to get the plate made locally. I'm going to see about coming up with a sketch and maybe a template to take down to the machine shop, along with the transmission, flywheel and clutch, and motor, to see what they charge for something like that. Wish me luck!

Next: Who knows? Could be anything from battery boxes to heater cores.

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