


There was no 100% consensus on the manufacturer but we were leaning Case based on the patent number.

Thanks for posting Al !

To put a bow on this the transmission is a Clark 425-T which George Teebay identified for me on the AACA 10 years ago. It was standard for 1 year (1930) in Pierce Arrow and an option in the REO Royale in 1931.
It is four speeds with 1st down and left and reverse over second and third over fourth. George spent 30 minutes on the phone with me today explaining it. I guess the ratio is wide between 2nd and 3rd and narrow between 3rd and 4th so practice is required to drive it. I noticed that today just driving up and down the driveway. Thank everybody for their help and especially George! Also Ed Minnie spent a bunch of time with me today on this.

These are the ratios. Note how the difference between 2nd and 3rd. You need to really rev it up to easily get to 3rd. 4th on the other hand is a small step up from 3rd.
1st 3.12
2nd 2.10
3rd 1.25
4th 1.00

I have added a folder to the library with many photos and instructions for rebuilding a Clark 4 speed.
https://reoroyale.com/library/folder/Clark%20Four%20Speed%20Transmission
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