1957 What Transmission Are These?

[Cuul59]

Hi. I recently picked up a manual transmission but not sure if it will fit my ‘57 T-Bird (312). One has a casting number of T89B-148 on the left side and T85C-1A on the right side. It’s paired with an OD unit that’s stamped R11-1P on the tail shaft. Any idea what I have and what it fits?

I also have another manual transmission with the numbers AB-7222-B and AB-7651-A on the tail shaft. Any thoughts on this one too? What might it fit?

Thanks, Neil

This page contains affiliate links for which I may be compensated. As an eBay Partner, and Amazon Associate I may be compensated if you make a purchase at no cost to you.

 

[jack-in-sac]

Do you currently have any transmission in your car? measure the length. You may need a change of driveshaft. A 3-speed B-W transmission is a mechanical device. A B-W overdrive is an electro-mechanical device The R-10 or the R-11 will suffice. The R-11 is more robust. Among other things you will need working a solenoid, a working relay, and a working governor. You will also need a cable pull for engaging and disengaging the overdrive. Do you have a kickdown switch? It is not necessary but useful. I have gotten away for 20+ years without one. If you look up Borg-Warner overdrive you will find sources of information. The oem overdrive for the '57 Thunderbird is longer than the 3-speed which requires shortening of the drive shaft. At least one source has a reprint of the overdrive manual. My '57 is a C-Bird ie. base 3-speed. I bought a parts car for my '57 Ranch Wagon and it had a T-85 overdrive transmission. This is one of the rare times I lucked out. It is the same length as my original B-W 3-speed. Although the overdrive portion of the transmission is considerably bulkier than a 3 speed or an actual T-Bird overdrive, it fits somewhat snugly in the transmission tunnel. It is tight but I worked that out. Apparently my OD is from a Mercury due to its painted color. It is also later as it has a fine spline input shaft. that was not a problem only requiring a change of disc. By the way my clutch is from a ranger and is a diaphragm pressure plate instead of the Borg and Beck 3 finger pressure plate. The shifter from a 3 speed is the same but the shift arms on the transmission are inverted. It is not a complicated changeover. It does require some work but nothing serious. I did some minor modification to ease my use but it was not necessary. Good luck to you.
By the way you will benefit form a shop manual and a B-W manual. One other thing is a bit of wiring but it is not complicated, see the manual. I suggest using different color wire and not all the same wire color.

 

[doug7740]