Transmission differences

AA Ford Discussion Group relating to the repair and restoration of your AA Ford.
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marcel kristoff
Posts: 32
Joined: October 26th, 2014, 1:00 pm
Body Type: flat deck
Model Year: 1928
Location: Fort St. John, BC, Canada

Transmission differences

Post by marcel kristoff »

I am working on bringing a 1928 AA back to life. It came with two transmissions (one with the multi disc clutch plates, and one without) but no engine. I have bought an engine for it and it is at the rebuilders place. We hope to take the head and oil pan off next week to see inside for the first time. The engine rebuilder has seen my truck and says that neither of the two transmissions will fit. He says they are just regular model A transmissions. He has rebuilt both A and T engines and also owns museum quality examples of each. He admits that this is the first AA truck he has helped with. I trust his judgement with the engine rebuild but need to know about differences in the transmissions. My truck has a timken rear end and is a Canadian model with a Brantford cab.

I understand that the 28 and 29s had three speed transmissions. What is the phyisical looking differences between the three and four speeds. Also, I read the term "two speed rear end" a lot. What is that about, and did the timkens have them?
Stakebed
Posts: 1223
Joined: June 14th, 2007, 7:29 pm
Body Type: Grainbox
Model Year: 1929
Location: Illinois

Re: Transmission differences

Post by Stakebed »

well in US AA's in 1928 the 4 speed didnt exist yet, that wasnt until late 29.

Up until late 29 AA's used regular car 3 speeds with a "dual high" right after them. Its kind of an oxymoron as its either a 1:1 ratio or a 2:1 ratio so its really an underdrive.

There was a high speed and a low speed rear end gear ratio on the worm drives, high speed is a 1: 5.14 ratio while the low speed is 1: 7. XX.


Canadian stuff im not sure about what trans they used nor am i familiar with the Canadian timken rearends....
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