overdrive

[duckroost]

Is it possible to install an overdrive in a 1930 AA 131inch wheel base truck?Thanks, Ray.

[Neil Wilson]

Ray,
The Warford company made a three speed under/direct/over drive which replaced the coupling shaft behind a four speed (Very hard to find).

The Warford for the 28/29 AA's with a Model A three speed are more common to find. These can be installed behind a four speed with the appropriate adaptors.

I have been told that Mitchall will provide an overdrive for the '30/'31 AA's. I have not investigated this however.

[duckroost]

Thanks Neil.I have a very nice 1928 AA flatbed with the "underdrive" with the three speed(controlled by lever on the floor).Is there a way to convert this underdrive to an overdrive?Just a thought. Thanks again, Ray.

[Neil Wilson]

Ray,
A friend had a local Model A'er convert a Dual High into an overdrive for his Model A. The unit was turned around and put into the drive line. I think that this has been done on a number of A's. So, I would think that this could be done for the AA drive line also.

If your truck has the 7.25:1 rear axle gear ratio, then there is not point in trying to install an overdrive until you replace the rear axle gears with the 5.14:1 gears!