1948 flat six Plymouth special delux transmission question

[Bern Pearson]

First, thank you to those who have graciously answered my questions to date.  You have saved me oodles of time and a bushel basket of twenties.

 

I have a 1948 Plymouth special deluxe with the original flat six and column actuated three speed transmission.  I plan on keeping the original engine as is.  The column actuated three speed transmission works fine.  The problem is that I want to drive the car long distances on the highway.  At sixty-five it sounds like the engine is two seconds from blowing itself apart.  (It would make a great sound effect for a single seat propeller fighter heading straight for the ground.)

 

I have a manual transmission with overdrive for a 1948 Packard.  Can I adapt it to the Mopar flat six?  Does anyone make an adapter?  Would the same clutch work?  Does anybody have advice on the plusses and minuses?

 

What are my other options?  What would the other options cost and where can I acquire the parts?

 

Is there a modern (less expensive?) four speed?  What about the gearing for the flat six's presumably lower RPM's and horsepower?

 

There is a shop in Tallahassee that will cut down the driveshaft if needed.

 

Many thanks,

Kind regards,

Bern

[Plymouthy Adams]

I would suggest a visit to the AACA pages and advertise that Packard OD for swap or sell and use the money to acquire a direct bolt in Mopar R10 unit.....

[Sniper]

The MoPar A833OD can be made to work, but you won't likely be able to keep the column shifter without some interesting fab work.  I've thought of using the column shifter for 1 thru 4th gear and an underdash lever/cable for R.  But thinking is where I am at there.

 

Those were used behind some fairly gutless slant sixes and 318 in the 70's and 80's. I have two of them, lol.  Half ton trucks are where you will usually find them and they are more than stout enough for a flathead..  The AoK guys make an adapter plate to bolt to your original bell, so your original clutch setup will work with a clutch disc change out.. 

 

Your speedo cable will likely be too short and depending on what speedometer pinion adapter (will most likely need to change the pinion to makes the speedo read right as well) is in the trans it may be compatible with a longer version of your stock cable, if not there are a number of sources for a custom speedo cable that can mate them together. 

 

Driveshaft will need to be custom since the A833OD uses a slip yoke setup and not a ball and trunnion.  I'd convert the stock rear end connection to a bolt on flange and get a modern style driveshaft setup.  Sure I am missing a few things as well.  Been looking into this swap.

 

Or go R10 for a more direct bolt in.

[Sam Buchanan]

Some folks have swapped out the rear end for a more modern axle with a different ratio.

 

Probably your best option is to adjust your expectations.....confine your travels to two-lane roads and enjoy the journey.  Life can be pretty cool at 55-60 mph in an old car.  ?

Edited February 12, 2021 by Sam Buchanan

[Eneto-55]

Just curious as to the manufacturer of the Packard overdrive.

[Adam H P15 D30]

Your only hope is if the OD unit has the same bolt pattern as the rear of the Plymouth case and the mainshaft can be swapped.  Both are unlikely as the last Packard OD I saw used the more common 4 bolt pattern on the OD case.

Sniper mentioned an A833 OD, My son has an 82 D150 /6 with this transmission and I would choose a T5 long before I would use the 833 OD.  With the /6 the gear spread is too wide and driveability suffers...

I ended up going to a taller geared rear axle with better brakes and it has worked fine for several years now.  I cruise at 65-70mph and hills aren't a real problem.  Actually I think I could out pull my son's D150, up to about 80 mph.  lol....  

[Plymouthy Adams]

2 hours ago, Eneto-55 said:

Just curious as to the manufacturer of the Packard overdrive.

should be the BW also...different case though...I think the Packard is a R11 unit.....Chrysler engineered the OD....instead of building another factory and gearing it up for production...they took it to BW who was already setup for the most part to go into immediate production...in exchange for the production of these unit for Mopar they allow BW to market them to other makes.  The world again benefitted from ma Mopar....BW made profits and kept folks employed at the same time.....

[Bern Pearson]

I am not sure how the responses work as I was going to reply to each one but can't figure out how.  Turns out that at some point I bought an OD R10.  Here are the photos. Will it work as a  direct bolt on and what suggestions does anyone have as to what I should do as far as refurbishing it?  If I pull the access plate and the gears look okay is it good to go?  Do I have to shorten the driveshaft?  What additional parts are required?   Here's the info on the case...  Any idea what it means?

GM

6

8945122

?E291  The question mark is because I can't make out the symbol   

 

5  RIOH-1

    W.G.DIV.

 

Will post the Packard info next

 

Many thanks,

Bern

[Bern Pearson]

I can't tell who manufactured the Packard OD trans.  It's caked with crud and the weather is not conducive to cleaning it.  I bought it with a freshly rebuilt 288 Packard engine and was told it worked.  The owner was converting a '48 four door sedan to a two door convertible and putting in a 350.  (It looked really nice.  He had engineered a folding top, which is amazing.)

 

BTW, I didn't and don't have anything to put the engine in, but it was a rebuilt Packard straight 8 for $1000.  I saw it running and he wanted less than the rebuild kit would have cost...and,  I always wanted one. (Gawd am I a sick puppy? )  At some point I want a rat rod so I am collecting parts.  

 

Here are the photos.  Perhaps it is obvious to someone who made it?  If the weather warms up, I'll pressure wash it and paint it and get back to you.

 

Kind regards,

Bern

[DJ194950]

The Bolt in Mopar R-10's are numbered R-10 G-1. I believe some R-11 were built also but seems most were for Fords and carried the ford letter after but not a G .

Other brands carry the R-10 but the Letter after tell the brands for which they were  made by BW.  For more direct to the brand fitments.  Main box and bolt patterns match their original make brand bolt patterns and do not interchange, sorry!

 

They do not mix and match.

 

DJ

[Bern Pearson]

Thanks for your response. 

 

Can I transfer the parts from my R10 over to the OD trans and then install it?  Or, is the dissimilarity somewhere else?

 

Kind regards,

Bern

[plyroadking]

Most of the internal R10 overdrive parts will interchange with R10s that were used on other makes. However the cases, input,  and output shafts are make specific. The governor drive gear does not interchange and the solenoids are different once you get away from borg's overdrives made for the big three. The Packard you have most likely won't bolt into your car, the input shaft is different for one and also no provisions for the parking brake either. I presume with enough ingenuity and machine work it could be made to fit though. I'd recommend finding a 1952-1955 Plymouth transmission with overdrive as it'll bolt right in and no serious modifications are required. 

[wagoneer]

I also recommend finding a nice needful Packard to put your rebuilt engine and trans into. Not a packard forum, but packard also need some TLC. 1948 was a good year. 
 

Everybody needs a second...or third classic car.

 

I’m in search of a very nice convertible or a truck, myself.

Edited February 15, 2021 by wagoneer

[Bern Pearson]

I have five cars and a divorce.  The Truck's a Toyota, so it doesn't even count.