Overdrive

Has anybody out there put a overdrive in a 1929 Franklin? Particully a "Mitchell". Any real problems do' s or don'ts?

Hi,

I have installed a Mitchell in two 1929s. (Technically, I installed it in one, took it out, and put it in another....)

The first one was a 135 Coupe. I used the mounting plate that mitchell provided, and I mounted it as far forward as possible because I didn't want the driveshaft in the back to be too short. This required that I remove the equipment box under the seat.

As I was doing it with the body on the car, I couldn't really get inside the frame channel to add angle iron, so I cut the mounting plate to size, cut holes in the bottom of the frame and put about 1/2 inch of spacers between the plate and the frame. The overdrive unit was still a little lower than I would have liked. There was a significant drop between the transmission and the overdrive. We put it all together and drove it 100 or so miles. Not too much vibration, but if there were I couldn't have done anything about it because the overdrive was basically bolted directly to the frame with no ability to adjust it.

We traded that car to a friend who took the overdrive out and put it Jeff's 3.92 gears. We were doing a body off restoration on our 137 Touring, so we had much better access to get it mounted correctly, and the extra 7 inches of wheelbase made it easier to place the overdrive so as to not interfere with anything. Instead of using the plate, we used two pieces of angle iron attached to the outside of the frame. This will allow for adjustments forward, backward, left, and right to make sure the overdrive stays more or less in line with where the drive shaft would have been, and we made sure that the front mounting was as high as possible so there wasn't a big drop in the small drive shaft from transmission to overdrive. The car is still being put together, so we haven't driven it, but hopefully it will work well.

Steve Roake had Mitchell install an overdrive in his 135 Sport Sedan. I drove the car, and the overdrive worked flawlessly. Steve passed away a few years ago, and I don't know what happened to the car, but Warren Martin might know. I bet if you called Mitchell and asked about Steve's car they would have lots of info about what they did.

Feel free to call me if you have questions. I'm in the Franklin register.

Rob

Thank you very much for the information. I will call you by phone late afternoon ,tomorrow to ask you a few questions.

Thanks again Frank