1948 Plymouth Transmission Swap

[Ronnie]

Can someone give me some advice on a transmission swap for a plymouth special deluxed sedan. Ive been thinking of swapping the transmission out of a 49 plymouth that has an overdrive, but i also have been thinking of purchasing a 49 chrysler windsor with a fluid drive near me. The goal is to have good gear ratios for in town and then be able to cruise on the highways without screaming the engine and gears. Any advice is appreciated. 

[Plymouthy Adams]

first, you either decided what car then proceed or ......buy both...........fix one at a time......

[Ronnie]

The 48 Plymouth is what I’m concerned with the 49plymouth and chrysler are too decayed for restoration but decent for parts. 

[greg g]

Do the od if it in good condition.  I just did the swap with 2 able bodied assistants.  Do you have the relay and wiring harness for the od?  By the way, the fluid drive and semi auto components are Not Supported by the Plymouth drive shaft flange and might need floor board changes due to longer overall length of the fluid drive unit.

Edited July 8, 2018 by greg g

[greg g]

The Chrysler does nothing to address highway rpm unless you change the rear axle the trans is a 1 to 1 final drive.

[Ronnie]

Thanks greg g that’s what I was looking for. I was pretty certain the chrysler would be no go, but just wanted to see what anyone else had done similar. The od on the 49 appears to be all there and in decent shape.  The guy selling it doesn’t know if it works been sitting a long time. So I guess I’ll take the chance and see what kind of shape it’s in once i get ahold of it. 

[DJ194950]

Any OD trans will help with your quest. Best if the 49 has an R-10 G Borg-Warner trans which is a easy swap if all the electric pieces are available.

 

Where do you live? Big mountains often driven? etc. will affect final gear ratios that would work best.

 

The Windsor trans, not so much unless you drive like a  grandma (not my grandma, she was a led-footed driver when she drove!).  Maybe the rear end gears could be of use depending on the gear ratio?

 

DJ

 

[Ronnie]

Well I scored the 49 plymouth with the r10g overdrive in it and everything looks to be there and intact. I’m excited now! I’m a bit of a young guy so this swap with definitely be a learning experience for me. Should be a perfect fall/winter project. 

[pflaming]

1) got a picture? 2) get a shop manual 3) a 49 with the ribbed bumpers is a special car, 4) if it is a driver, for starters, just clean, shine, tune and drive it, then change per your tastes. One priority in my opinion are front disc brakes and all new brake lines.  Welcome, enjoy the ride. 

[Ronnie]

Thanks pflaming. Unfortunately it wasn’t in quite good enough shape to drive. Been sitting awhile, but it’s all there just frozen in time. Yes I saw online there’s a manual just for these overdrives. (Whew). That’s the only real modern upgrade I’ve made and it was when I was just 16 when Plydo was still around and I got a conversion kit for front disc brakes on the front. 

[pflaming]

That black, gray, rust original paint is killer.  This IS patina, nothing fake here, and the original chrome, a winner. TKS for the picture

[greg g]

As mentioned,l just (400) miles ago,completed an od install. My thread was titled large hole in the floor.  Not really high on detail or pictures, but will give you some insight into the procedure.  Feel free to shoot questions when you get busy with it.

[Young Ed]

FYI if you go looking for 49 OD manuals you won't find anything as that 49 would have been an OD swap itself. Plymouth didn't start installing them until 52. 

[MarkAubuchon]

Young Ed, you caught it before I could comment.  49 didn't have OD

[DJ194950]

Anyone want to open the car-o-worms about if the factory started installing the OD's in late 1951 vs. 1952?  ??

 

DJ

[Young Ed]

28 minutes ago, DJ194950 said:

Anyone want to open the car-o-worms about if the factory started installing the OD's in late 1951 vs. 1952?  ??

 

DJ

Just like now the model year started in the fall the year before. So 52s built in 51 could have OD. Also with the Korean war going on and Chryslers war contracts they almost didn't built 52s. The 51s and 52s are all lumped together as P23s.