I have a stock 1950 Mercury and am wondering what Borg Warner overdrive transmission would have been installed at the factory.
The transmission itself is the stock Ford built 3 speed transmission. The overdrive unit fitted thereto for overdrive equipped vehicles was the BW R-10 model that was widely used by most American manufacturers during the late '30s through the '60s/'70s. Some of the heavier, more powerful cars of the period used the R-11 model, though not the Mercury. Ray
I don't think it is as easy as just bolting an overdrive on the back of the regular 3 speed case though.
Thank you Ray for your "to the point answer". Do you know if that stock transmission would be the T86 that is often referred to?
There is no shortage of '49- '50 Mercury overdrive transmissions for sale. If you're serious , run an ad.
Don't mess around trying to adapt another version OD trans. Get a 49-50 Merc complete OD unit......or the early 51 unit since it's the same. Also, you can't "bolt on" an OD unit to an existing standard trans.....there are too many differences in the case and mainshaft to allow this to work.
Thank you all for your replies. Perhaps I should back up a bit and address my reason for asking these questions in the first place. When I engage the overdrive while driving, the car will go into the "free wheeling" mode, but it does not shift to a higher gear as it is supposed to. Any thoughts or solutions will be greatly appreciated.
Check that the cable is adjusted correctly. When you do figure it out it will be an entirely different driving experience.
If the cable adjustment isn't the issue, check and/or change the lubricant in the OD unit. It uses a separate oil supply from that of the transmission, although they both use 90W GL4 gear lube. Do not use GL5 as it is harmful to 'yellow metal', i.e. br***, which is found in the synchronizers in you trans and I think is also in the OD unit. GL4 is much more difficult than it used to be to find, but is available on line. I sourced some from Redline. My '49 Plymouth (later OD trans) does tha sometinmes when it hasen't been driven in ahile, but usually after two or three attempts it engages. I don't think the fuse has anything to do with it as, so far as I know, the fused circuit is for the solenoid which disengages the OD unit when the accelerator is pressed to the floor. Ray