1950 Mercury add factory OD

[Sixseven]

My car has no overdrive and wondered if the factory set up is difficult to find. I've not been looking long enough to see any availability. I suspect it would bolt onto the transmission but I'd have to swap the drive shaft and add the control cable.

[Bob C]

I think the driveshaft is the same but you will need the whole transmission.

[tubman]

And the relay on the firewall and the lockout cable and the kickdown switch and the wiring harness. Thankfully, all are (or used to be) available but it can get expensive.

[Jumbogem29]

Cheaper for you to go with a C4 if you have a flat head .

[tubman]

Originally Posted by Jumbogem29

Cheaper for you to go with a C4 if you have a flat head .

I don't know if I agree with this. You still end up with a 1:1 final drive, which is counter to the purpose of adding an overdrive.

[pistonbroke]

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The overdrive for your car is still fairly common at swap meets and on line like fleabay. Talk to mac Van pelt . He may be able to steer you in the right direction. I believe the one for your car uses the earlier style bell housing like the 49 merc but not sure. You will love it once it's in. I've put them in all my old rides and drive them all over the lower 48 and Canada. Tim

[Pvmt-Pndr]

I see your signature shows your merc is a woodie. Station wagons came with 4.55 gears if I remember correctly. If you have a hard time locating all of the parts for an OD transmission, see if you can find a rear end from an OD car - they have 4.27 gears or even a non-OD car with 3:91.
I know it's not what you asked for, but options are always nice to have.

[Sixseven]

Thanks guys. The chassis manual definitely notes specific parts for the 1950 and shows all the relays, cables, etc required. the trick is now to be able to identify the correct trans for the 1950 bellhousing while checking adds or flea mkts. Swapping the rear axle is a great idea to consider as well. 3:91 would work just fine.

[Zax40]

What OD transmission would have came in a 50 model? I didn't think that was offered until the Y Block replaced the flathead

[mcgarrett]

Borg Warner overdrive transmissions were available for Fords & Mercurys starting in 1949. I still see them at swap meets. The Mercury '49-'51 units were different from the Ford, so you will need to look for the Mercury unit. If you have good overall mechanical skills, they are not difficult to install and work well.

You will need the complete transmission/overdrive assembly for a '49-'51 Mercury, firewall relay, kickdown switch (goes under the accelerator pedal), control cable, and drive shaft or have yours shortened. You can make your own wiring connections. I don't remember if the speedometer cable needs to be changed along with possibly a rear motor mount - I forget. Others may chime in with other items I might have overlooked.

[38 coupe]

If you are willing to forgo some of the automatic features of the factory control system you can use much fewer parts to install the overdrive. The minimum you need for easy install is the transmission, a good solenoid, and the lock out cable. An on-off switch to run the solenoid takes care of shifting in and out of overdrive. For anyone going to Auburn I can demonstrate this in my 53 Ford.

The 49-early 51 Mercury transmission looks like this:

[mercman from oz]

The 49-early 51 Mercury transmission looks like this: - 38 coupe

[pistonbroke]

The kick down switch , relay and control cable from a ford will be he same although the handle on the cable may have been chrome of black for Mercury. Napa still sells the kick down switch and I think I still have a relay if you cant find one. The small warner overdrive guts are all the same from ford , gm and mopar so there are lots of good used and NOS parts out there . Only the main and tail shafts and tail housing are different. I've used the 49 - 51 Mercury overdrive in the 48 thru 52 F1 pickups . They are a nice , simple and good working unit. Tim

[wga]

I added an OD to my 49 wagon and did not change out the rear axle gears. Added this relay last year. Works as it should. Mounted it to the brace above the left side kick panel. Ran the wires down the kick panel across the floor under the trans cover. Wrapped in Teckflex loom.
https://vintageautogarage.com/borg-w...elay-12-volts/
Adding the kick down switch was a hassle for some reason. When I did mine, took the time to replace the motor mounts. Be sure the rear bushing and seal are replaced.
Used the same drive shaft. Check your axle seals for leaks. While you are wrenching in those areas, easy to replace.

[mcgarrett]

Before installing the relay, look closely on the drivers side of the firewall in the engine bay and you should see a couple of factory pressed dimples with the exact spacing for the overdrive relay. Use a small drill to open the holes for the screws. At least, I found them there on my '50 Ford.