Inliners International Forums General Discussion Ford 4 banger guys! anyone ever mate two model a trans to get overdrive??

I'm looking for period correct late 1930's -early 40s overdrive ideas for an early hot rod I'm building.

I know a fellow out in CA by the name of Dave Kruger mated two model A transmissions together successfully,...this gave him overdrive,...spoke to a friend of his and he tells me they were cruising at 85 comftorably going to Paso Robles in a Ford 4 banger! it can be done successfully,....I'm just hoping someone has done this in here and can tell me how, etc.

Thanks in advance.
J.

Maybe Secrets of Speed Society (Ohio) is onto something. Have you inquired there?
I've done some head scratching on this for some time. Looks like the second transmission would be installed backward using a lathe-built coupler housing with the U-joint as the shaft coupler. Low-reverse on the rear transmission would be ommited. 2nd would be your overdrive, high would be direct drive. Lock the gear shifter into the 2nd/high gate. Respline the output shaft (previosly the input shaft) to take the U-joint. An adaptor plate can be fabricated to mount the rear bearing retainer/torque tube ball socket. Torque tube and driveshaft will have to be shortened accordingly. Speedo gear and rear axle gear ratios are co-ordinated, so speedometer accuracy is not affected. Only engine RPM will be reduced while in "overdrive". Let's get some feedback on this idea. Has anyone out there done this conversion?

See same post in engines section this board for how and why. Speedometer will be affected when using over drive because trans is in backward and you are overdriving it after the speedo gear. Second gear needs to be shiftable to take it out of OD. The first reverse slider can be removed to reduce rotating wait if so desired.

I've run Model A's for years with 33% Borg Warner conversions which would be period correct for 30's and 40's. 85 mph would be a stretch.BW OD's came from just about all cars except Fords and Chevys prior to 1949.

Columbia was used in Fords.

Your speedo gear is attached to the front of the the torque tube, AFTER THE OVERDRIVE, not before it! Your overdriving unit is in front of the speedo gear. Richard, were these Borg-Warners a direct aftermarket fit to the Model A transmission? Are these the ones you find sometimes on Model AA trucks or are these underdrives? Just curious.

The Borg Warner OD's I'm talking about are taken from an old car like Studabaker, Plymouth, Nash whatever and spliced into the torque tube. There are hundreds running around in Model A's but the more modern and new Mitchell has become the most popular.