randyta

36 Plymouth Overdrive Transmission

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Thinking about putting an overdrive transmission in my 36 Touring Sedan.  I can run 50 mph or so but the engine is working pretty hard.  Was thinking if I had an overdrive trans I could drive at 55 or 60 and the engine would be happier.  Does anyone know if an overdrive trans was an option in 36 or was it something that was an after market item that was available at a later date?

Thanks,

Randy

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First Plymouths were in 51 or 52.  You can check at the P15/D24 site to see if any other Chrysler Overdrives could be made to fit. Some very knowledgeable folks there.

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I think that an overdrive transmission was available for the '36 Dodge and saw one for sale at Hershey several years ago for around $3,000. I would imagine that it would fit right in your Plymouth but you'll also have to change the drive shaft.

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Jpage is correct, you can bolt in a R6 overdrive transmission and shorten your driveshaft. The R6 I have came out of a 1939 Chrysler, it is the older top loader style case with a creative top cover that converts it to the 1939 rod and cable shift linkage. You can pull that cover off and bolt on your standard 1936 floor shifter. I'm not sure about the parking brake as I can't recall if it was still a floor lever style in 1936 so you might have to get creative as my '39 R6 does not have the provisions for a floor lever. $3000 seems really steep as there was one on eBay several months ago that went for around $500

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Concur with earlier posters about Plymouth not offering a overdrive in that era but that one from another Chrysler make can be made to fit.

 

However I wonder about your actual need. Maybe your engine is worn out, but if it is in reasonable condition it was designed to run all day at 3000 to 3200 RPM which maps into about 65 MPH for most of the final drive ratios and tire sizes used by Plymouth in that era. Just because modern cars are cruising at lower RPMs at that speed doesn't mean that you have to retrofit an older car to do the same.

 

Cost of getting a good overdrive transmission (or getting one not so good and rebuilding it) is not that different from rebuilding your engine. So it the issue is the engine is worn out your financial outlay will be about the same. And even if you have an overdrive transmission, you probably don't want to be driving around with a worn out engine that could be a reliability issue.

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I think that an overdrive transmission was available for the '36 Dodge and saw one for sale at Hershey several years ago for around $3,000. I would imagine that it would fit right in your Plymouth but you'll also have to change the drive shaft.

From what I have read, only exports had the OD installed on the 30S Dodge and Ply. Chry and Desoto had them as an option.

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I have a OD trans from a 40 Chry 8. They are much stronger than the ones in the 30s. It is on its way to George Ashley in PAbe converted and rebuilt. They have to change the input shaft and a few other mods. A custom floor shift is also being made because it's a side shift trans. You would have to fab  the e brake.

Edited by countrytravler (see edit history)

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I knew an older man who lived in the neighborhood who had a '36 Dodge. He said he found it quite easy to install a post war differential (with more favorable gearing). I don't know for sure what was involved, but  I do know that he had to chisel off and reuse his old spring pad mounts. One of the benefits, he said, was that he was able to use the larger post war backing plates, drums and brakes. They were a simple bolt on. He also upgraded the front brakes at the time. Again, a simple bolt on.

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Dave, forgive my ignorance, but could you be more specific about which cars are "A" body?

Dodge Darts and Demons, Plymouth Valiants and Dusters 1967-1976.

Edited by keiser31 (see edit history)

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Plus Cuda till1969.

Yes, as Dave says, the Barracuda from 1967 through 1969. The earlier Barracudas, Darts and Valiants were 'A' bodies, too, but with a different engine compartment configuration (smaller). That was from 1963 through 1966.

Edited by keiser31 (see edit history)

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1964 to 1969 Barracuda rear has the same dimensions. Yoke may be different. Also 2 different bolt patterns. 4" and 4 1/2 was used. If you are going to do the swap, make sure you have the 4 1/2 bolt pattern.

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I only brought up the subject of rear end swaps because it seems that guys frequently ask about overdrives for these pre war cars. Some of the limited number of Chrysler product o'drives do bring some hefty prices. I don't really have an opinion as to which route is better. One thing that always struck me as fortuitous about the post war rear end swap was that the same parts car that supplied the rear end (which had the larger brakes than the pre war car) also provided the same larger brakes for the front in a simple bolt on package. In any event, I encourage anyone who increases the highway speed of their pre war car to explore ways of increasing the braking ability of their treasure at the same time. I'd hate to rely on my stock '36 brakes when someone cuts in front of me on the freeway.

Edited by Hudsy Wudsy (see edit history)

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Just have to drive careful. I'm a 18 wheeler car hauler semi-retired. 2 million plus miles and I have never stood on the brakes. (lock them up) 

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Dave, not to be argumentative, but even when your rig is fully (legally) loaded it's operating within the parameters of it's designed brake system. No one designed our pre war cars to go as fast as modern freeway speeds and stop as quickly as modern cars must to avoid trouble.

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I drove a '37 Chrysler Imperial from my town to Winchester, Va, about a 3 hr. trip, at speeds up to 65 with no stopping problems. A properly restored braking system should work as good as new, but they aren't disc brakes! Most of us have driven many miles in vehicles with drum brakes and had no real issues.Even ABS won't stop you on a dime in an emergency!

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The 18 wheeler, or my pusher motor home for that matter wont stop nearly as well as a properly sorted vintage brake system.

Some states require a special license to drive air brakes.

Basically don't tail gate and leave yourself ALOT of room.

The dangerous ones are those around me that don't understand that I cant stop in a hurry.

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What I was trying to say is that you have to drive way ahead of yourself. I didn't say anything about stopping distance or what brakes were capable of. I stated that I have never locked my brakes up. (Smoking the tires)  I have driven in all major cities sometimes being 90.000 lbs. I have driven on ice and have never had my trailer come around me for breaking to hard. You have to drive defensively and watch out for the other guy. My dad was a professional roundy-round racer in the 50s. He taught me to drive a car or truck and pretend that a brake pedal don't exist. All my years of driving, (street racing, normal family driving, drag racing, my 15 tow trucks with 2 heavy duty, and driving a 18 wheeler) I can only remember locking my brakes up one time. A horse ran across the road and I was driving my mom's car, a 66 Ford Country Wagon that she just bought. It was a 390 4 speed car. I was 16 and that was in 68. Knock on wood, I probably have driven 3 to 4 million miles in my lifetime and never been in an accident that I hit someone. I have had people rear end me and t bone me when the person ran a red light. So, I guess my system works. And the 30s Mopar, the brakes work just as good as the cars in the 70s with drum brakes. Cars in the 70s average speed  was 80 mph on the expressways. Speed limits in some states was 70 plus until the oil embargo.

Plus all the vehicles that I have owned very seldom would need brakes done. I have done 500.000 miles on a big truck before it would need brakes. I own a 2007 Dodge Ram 3500 with 45.000 miles, just changed tires because of cracking on the side walls. Happens a lot here in CA. Plenty of tread left. The brake shoes are at 90% left and we haul a 2 car trailer that is 21.000 GVWR behind this truck. Half the miles are city. It also has an exhaust brake that helps a lot in stopping. I have had people say that my brakes lights don't work. NOW! that is funny.

Edited by countrytravler (see edit history)

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I only brought up the subject of rear end swaps because it seems that guys frequently ask about overdrives for these pre war cars. Some of the limited number of Chrysler product o'drives do bring some hefty prices. I don't really have an opinion as to which route is better. One thing that always struck me as fortuitous about the post war rear end swap was that the same parts car that supplied the rear end (which had the larger brakes than the pre war car) also provided the same larger brakes for the front in a simple bolt on package. In any event, I encourage anyone who increases the highway speed of their pre war car to explore ways of increasing the braking ability of their treasure at the same time. I'd hate to rely on my stock '36 brakes when someone cuts in front of me on the freeway.

I have seen articles in our library that a lot of these cars built in the 30s was capable on speeds of 75 MPH. A lot of export Dodge and Plymouth cars was equipt with the ODs. We have a customer with a stock brake 1936 Dodge truck that cruises all over Northern CA and Southern OR with no brake problem.  And that terrain is mostly hilly. And he says he likes driving in the 65 ranch. Just saying.

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so have you ever thought about using a t5  s-10 conversion to get the overdrive --- I have seen the adapter plate for the switch --also have seen 2 cars with it done ----not sure what they do for a park brake --- the older o/d are hard to find and  parts are almost impossible---just a thought 

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They make a disk brake emergency brake kit to bolt behind the trans. Paul Curtis in MI sells the kit for the OD conversion. I think Summit sells the E brake set up.

Edited by countrytravler (see edit history)

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