1937 / 1938 De /Soto Overdrive

[Richard Cope]

Hi

Recently acquired a transmission / overdrive from a 1937/38 Desoto.  It is an R6-1, T86-1P, the unit has been rebuilt.  I want to put in a 1939 Plymouth P8 Business Coupe, with stock engine, the current transmission has been converted to a floor shift & floor panels changed.  Does anyone know of any available literature for this unit?  As I understand it is mechanical and a push / pull cable is used to engage / disengage and if engaged the unit will go into overdrive around 30 mph.  The emergency brake cable is on the opposite side, hoping that the current cable can be moved to that side?  The drive shaft will have to be shortened.   Is anyone aware of any other issues that may come up during installation?  

Thank you in advance for your help.

Regards,

Richard

[dpollo]

The 39 Shop manual has a very detailed description of the Overdrive, which for 39 incorporated a kick -down feature but is otherwise 

very similar to earlier units.    Plymouth offered overdrive on export models but units were available on Chrysler.   As for the parking brake, you may have to re route the cable.   This installation should present very few problems.  The drive shaft will need to be shortened.

[Pete]

I'm also looking at putting an R6 overdrive in my '39 Plymouth P8. A couple of questions:

 

1) It looks like I want an R6 out of a '39 Desoto or Chrysler 6. I have the original column shift, so it would need to be a '39 to avoid changing the shift. I recently rebuilt my transmission, so I would like to add the overdrive to my current transmission. Is possible to add the OD to my transmission, or do I need to change the whole transmission & overdrive? Are the transmission (minus the OD) part numbers the same across the three makes?

 

 2) It appears that the R10 is much better supported in the current aftermarket. Does anyone know of a source for re-pops or rebuilding services for the R6 for such things as the solenoid and governor?

 

 3) I remember reading somewhere that you can put an R10 in a '39 Plymouth, but you will need to modify the chassis X-member. Does anyone have information on that swap?

 

 Thanks in advance,

 

 Pete

 

[Richard Cope]

Pete,

 

I haven't received the overdrive yet,  below are a couple of photo that I received.  The top of the transmission looks to be the same as the 39 trans, therefore appears possible to change the top and rails and it could be converted to a column shift.  When I changed my column shift to a floor shift was just a matter of changing the top plate & rails.  Also had to change the floor from a P7 to allow for the floor shift.  I personally like the floor shift, but would be easy to change back to a column shift.  Appears that the R6 unit uses the same top plate as the 39 Ply.  When I get it in a couple of weeks will upload photos.  Appears hat the R6 is an easier swap for the 39.  I'm hoping that the second gear is the same ration as the 39.