overdrive questions?

[Flatie46]

I found an overdrive from a 1954 plymouth and was wondering would it fit and work in my 46 plymouth? I can get it pretty cheap, I dont know what the goin rate is on one. I never thought much about one cause I never thought I'd run accross one. I rounded up a t-5 a while back but havent worked tword gettin it in yet. I found this od, dont know what kinda shape it's in, still in the car and seems to be all there. I don't know nothing about these od's if I buy it is there anything I need to be sure to get when I grab it? Would I be better off with the T-5? Can you buy parts for the od? Skool me up on this

[Young Ed]

Yes it fits in your car. The only diff in the main tranny is the speedo cable moves to the other side. Simple fix. You also need the lockout cable and handle from the interior and then the kickdown linkage and the relay from under the hood.

[RobertKB]

If you can get it pretty cheap, at least get it on spec. They are worth quite a bit of money. I could have gotten a whole car with an overdrive for $100 but let it get away as I already had a parts car I was taking apart and no room left for another vehicle. It still hurts from kicking myself.

[Captain Neon]

Which model overdrives should a fella be on the look-out to put in a P15? Which MoPars might have a workable OD to mate with a standard 1946 Plymouth transmission? I am giving serious thought to planning a trip on the Mother Road (Rt. 66) from Springfield MO to LA and back once I can get a good OD installed. I don't want to get run over in LA traffic. I have debated the benefits and limitations of OD vs. a faster rear end for years. Living in the Rockies for a year and having driven the El Raton Pass last spring has made me give more thought to an OD.

[Normspeed]

You'll like the OD when you get one and get used to how it shifts. These days I seldom use my clutch pedal except with full stops and starts. OD doesn't need the clutch, it shifts smooth if a bit slow.

Using a simple splitter switch you can drive it as a 3, 4 or 5 speed. You can, if you wish, be traveling at any speed, let off the accelerator and the motor will idle and you will coast (freewheeling) Or, if you're pulling into the local Sonic on the boulevard backing down from 35 mph and you want to hear some popping and grumbling, you can switch off the freewheeling OD and you have your engine braking back.

In L.A., at your good OD speed of 70 or so, they will still run you over.

[martybose]

You can't just add a later overdrive unit to your existing tranny, as the electric OD's require a modified transmission that extends a shaft so that the OD is locked out mechanically when you shift into reverse.

I had an OD unit out of a later Dodge in my 47 for a lot of years before I got around to figuring out how to wire up a 12V system to operate it, and all I can say is I should have done it a lot sooner. Where before I used to run at 55 in the slow lane with the engine screaming, now I can cruise at 65-70. A good addition for our cars.

Marty

[jimainnj]

Marty Are all the overdrive units 12 volt?

[Young Ed]

Nope most are 6v. Only a 56 until would be 12v

[blueskies]

Which model overdrives should a fella be on the look-out to put in a P15? Which MoPars might have a workable OD to mate with a standard 1946 Plymouth transmission?

The overdrive to get is the R-10 model. The overdrive is coupled to the transmission, and can not be mounted to your existing transmission. There are internal differences in the overdrive transmission. The whole assembly is, however, a direct swap for your stock three speed.

...is there anything I need to be sure to get when I grab it? Would I be better off with the T-5? Can you buy parts for the od?

Make sure the ovedrive is an R-10. Parts are available still. The T-5 swap requires some fabrication to install. The R-10 overdrive is a bolt in swap for your stock three speed.

Marty Are all the overdrive units 12 volt?

The R-10 ovedrive was made in both 6v and 12v. The relay and solenoid need to match which ever voltage you have on your car. If the overdrive you get does not match your voltage, you can simply swap the solenoid and relay for the correct voltage of your car.

I rebuild an overdrive for my '50, you can read all about it by clicking here.

Pete

[BobT-47P15]

Hmmmm......now, all this talk about 6v and 12v makes me wonder which

voltage my overdrive is. It was attached to a 1957 Plymouth engine, which

was being used in a 1951 Plymouth car. I don't recall ever talking to the

guy about what voltage he was running. Now, if I can find his information,

I'll try to contact him with the question. I think he actually has that same

car after all these years.

Just how do I tell which voltage it is......will hitting it with 6v not work a

12v item?

[Suddensix]

I've been running a 6 volt overdrive solenoid on 12 volts for 3 years with no problems. I don't believe 6 volts would trigger a 12 volt solenoid.

[kevinanderson]

I don't know if anyone had stated this or not, but get the drive shaft, and follow all of the wiring off the transmission and pull the relay off the firewall and kickdown switch off the carb. I put an OD out of a '54 into my P15. It was a chore, but it was basically a bolt in.

[Young Ed]

The OD is the same length as the standard 3spd so the driveshaft doesn't change length. Also FWIW the OD is only about 1/2 in different than a gyromatic and the same driveshaft can be used there too.

[Jim Yergin]

I don't know if anyone had stated this or not, but get the drive shaft . . .

Why? I was able to use my original driveshaft in my 1941 P12 with the 1954 Plymouth overdrive I installed.

Jim Yergin

[Flatie46]

Is an od from a 54 fury an r-10? Kick down switch on the carb? will this switch work on my 46 carb or do I need to get the carb too?

[martybose]

Is an od from a 54 fury an r-10? Kick down switch on the carb? will this switch work on my 46 carb or do I need to get the carb too?

If your car is hopped up in any way you'll probably find that the OEM kickdown switch is more trouble than it is worth. A lot of people (myself included) mount a manual switch on the shifter to perform this function, which also gives you the option of doing things like making it a 5 speed (the gearing is such that using 1-2-2OD-3-3OD is actually spaced better than 1-2-3-3OD. When getting on the freeway I often use 1-2-2OD-3OD, as 2OD is a great gear for getting up to freeway speed!

Marty

[Californian]

I found an overdrive from a 1954 plymouth and was wondering would it fit and work in my 46 plymouth? I can get it pretty cheap, I dont know what the goin rate is on one. I never thought much about one cause I never thought I'd run accross one. I rounded up a t-5 a while back but havent worked tword gettin it in yet. I found this od, dont know what kinda shape it's in, still in the car and seems to be all there. I don't know nothing about these od's if I buy it is there anything I need to be sure to get when I grab it? Would I be better off with the T-5? Can you buy parts for the od? Skool me up on this

flathead46, Your 46 should have a 3.9 rearend , and if your engine is strong it may pull that gear ratio.the MoPars equiped with O/D, came with a 4.11....

To check the gear ratio, look on the the third member there is a flat spot on bottom of the case off to one side, that has the factory gear ratio stamped on it...I know this has ben talked about , but it bears repeating, get the kick down switch and the wiring , Set up a normally closed button style micro switch on the dash and run your hot wire off the ignition switch that goes to the ignition coil through this micro switch and when you want to kick down out of third over ,but you don't want to floor the gas pedal you just hit your micro switch,, I think someone I read about put their kick down in the end of the gearshift knob....

And when you check the trans out by hand, with the O/D lever in one postion turn the trans imput and the output will lock up with the trans pilot shaft and with the lever in the other postion it will lockup in one direction of rotation and freewheel in the other direction of rotation, if not there is probbly something wrong in the O/D unit of the transmission..

So if its still in a car,get everything as mentioned before get all of the electrical parts related to the O/D., including everything from the trans on back including the rear end included that way you will have what came with that MoPar with a O/D unit, if still stock original equipment, if nothing was changed it should be a 4.11 rear end...

Just passin on what I learened about O/D's from different folks along the way and incorporated into a 48 P15 Deluxe I had during the the 1970's...

Tom (09)

[Young Ed]

Correct factory gear ratio is 4.11. All of our OD cars have a 3.9 behind them and function just fine.

[martybose]

My OD works great with a 3.9. In fact if I ever get to the point of changing rearends I would probably go for something like a 3.7 ratio.

Marty

[blueskies]

...I think someone I read about put their kick down in the end of the gearshift knob....

I have my kickdown switch mounted on the end of my gear shift lever. I like it much better this way than on the throttle. I can downshift any time I like without full throttle. And as mentioned above, it allows split shifting up through the gears, like a five speed. More on this here.

Correct factory gear ratio is 4.11. All of our OD cars have a 3.9 behind them and function just fine.

I too have the 3.9:1 rear end, and think it works great. I live in the mountains of Idaho, and

and maintain speed at the same time.

Pete

[Normspeed]

I took Pete's idea and made it uglier. Works great. Also, you may not need the driveshaft but it wouldn't hurt to grab it while you're there, but definitely you'll need the e brake drum which is different on an OD. Here's a standard P15 3 speed ebrake and a 53 OD ebrake.

[blueskies]

Here's a standard P15 3 speed ebrake and a 53 OD ebrake.

Norm-

Which one is which? I didn't notice a difference on mine...

Pete

[Young Ed]

We've never had to do anything to the ebrake either. Only time we did was from the dodge gyro which had the expanding type

[Normspeed]

Darn, I can't recall which was which. Maybe mine was different because it's a 53. I do recall that one of them would bind up on the OD while the other worked fine.

[blueskies]

Darn, I can't recall which was which. Maybe mine was different because it's a 53. I do recall that one of them would bind up on the OD while the other worked fine.

The one on the right looks like mine. If I remember right, I used the ebrake assembly from my '50 three speed because it was in better shape than the one on the '55 Dodge OD transmission.

Another question about these drums... is the drum through-bolted on to the hub with the driveline bolts, or is is it pressed on? Reason I ask, is my drum rattles when I take off in first gear, even though my driveline bolts are very tight, as is the nut that holds the hub to the output shaft on the OD. Drives me nuts...

Pete