Packard Forum Index » Post-War (1946-54)

Hi everyone

I have been offered a secondhand overdrive gearbox from a 1948 eight cylinder Packard can anyone help with advice ?

My car is a six cylinder with the standard three speed box

Both cars are 22nd Series and right-hand drive

My queries are : mechanically will this simply replace my gearbox complete as one unit or can the overdrive be attached to my gearbox ? How difficult is the wiring on the overdrive unit - I understand it has solenoids ? How is the overdrive controlled within the car ? To fit the O/D does the prop shaft have to be altered ?

Does the work involved (and costs) outweigh the advantages of better gas consumption etc. ?

My car is progressing - photos attached

Best regards Michael

Attach file:

---

  (134.37 KB)


  (49.41 KB)


  (47.27 KB)


  (130.22 KB)

Car is progressing nicely & like your color choice. Is that the new demister you found locally? It almost looks like it might have been there for 60 years.

There were two overdrives available. The cars would probably have had the R9 when new. Those had carried over from prewar and was replaced by the R11 in 49. There was a program where the R9s which were sometimes temperamental could be replaced with the newer units so it is possible the later is what you have offered. The entire trans and OD assy is changed as a unit. Driveshaft is shorter and there are some different and additional brackets for cable controls and switch mounting needed as well. There were also some gearing differences in the rear axle but I can't speak directly as to what kind of results you would have if that was not changed. If you have access to the parts car, and it is fairly complete would be a good idea to get as much as you can.

The R11 would be the easiest electrically as there was only 1 relay and a couple of switches as compared to the older unit. That one was much more complex electrically and mechanically. R9 electrical parts are starting to be hard to find and expensive. R11 components are being reproduced as they were used by lots of other cars in the 50's. The manuals for both units are available on site--look for econo-drive for the R9. The R11 is covered in the Borg-Warner OD book as well as a service counselor from 49.

As to the advantages, it seems to be a popular upgrade over here lately but will let those who have made the change answer that question.

The overdrive transmission is a bolt-in. Other parts that go with it are the lockout cable, governor and relay. The lockout cable is unique and has a bracket with a switch that mounts under the instrument board. The governor is installed on the overdrive unit and the relay goes on the engine compartment side of the firewall. Driveshaft will need to be shortened.

I would encourage you to do the work to install the overdrive. It will give the car much greater flexibility under all conditions, and will enable you to cruise at 70 with the same engine revs that used to provide 50. Helpful in the modern world. I am guessing that your car might already be geared 4.3 or 4.55 to one. The differential housing is stamped with the ratio at about the 11 o'clock position as you face to the rear of the car. The overdrive will give you an effective ratio of 72% of your axle ratio, or in the case of a 4.55, 3.28:1. That is a nice difference. And, you can always lock it out while traversing Snowdonia.

Hi HH56

Thanks for compliments on the colors - took a hell of a time to decide on them as the Wife got involved !! The heater unit is an after market one by Clayton, a company over here who have a specialist dept. for classic cars - does look the part though I agree.

Thanks too for the info.- sounds like a BIG job - I'll have to discuss purchasing the parts with my Restorer - "driveshaft" I assume means PROPSHAFT in UK ? If so I have to also purchase this item too !

Best regards Michael

Michael,
I ownd a 39 six that originally had no over drive; however, 39 was the first year Packard offered an OD, but the only year for the R6/7 asd in 1940 the R9 was offered. I found an R9 and it bolted right in (as mentioned by others)> I needed to extend a hole on the frame X member to allow the solonoid to have room, but I think the 48's accomodate the OD as is.

Now that I have the system, I would now never want to go without it. It is a pleasant and well performing system. My only wish is that the engagement speed would be a bit higher, but it is not bad.

As others have mentioned, the function of the electricals is accomplished differently between the R9 and R11, and the R11 is definitely simpler. I was fortunate to find a system with all the items needed and perhaps more fortunate to have found some spare items at swap meets. With that said, I would state that both are very reliable and provide a great ride.

What I don't know is if there are any Right/Left Hand drive implications. I would still say it is worth the effort.

Pat

Thanks Brian for the info.

Obviously I need to make sure that the guy with the Gearbox and O/D unit has all the parts you mention.

Best regards Michael

Hi Ross

Most helpful - I'll look up the ratio stamped on the diff. housing - also thanks for the calculations. In theory this
would be a good mod. on my car - downside is what it is going to cost to get the bits (and has he got ALL the bits)and also what's the cost from my Restorer to actually change everything.

I'll keep everyone upto date as things progress

Best regards Michael

Hi Pat

Thanks very much for relating your experiences with the O/D unit on your car.

The donor vehicle is a RHD as is my car so all should be okay in the swopping department

Best regards Michael

I just finished putting an R-11 OD tranny (out of a '53) in our '41 Clipper. It was a real "bugger" to get through the "X" in the frame, and I didn't want to cut the hole larger so we "stretched" it a bit with a pry bar and got the unit back far enough for the shaft to clear the housing.
FYI: Also consider the drive shaft. We had to build a new, customized drive shaft because the old Clipper shaft had a large tube that tapered down on the ends for the yokes. We had to shorten it about 9 inches so a new smaller tube was in order to accept the new yokes. We then put the old style u-joint on the rear-end end, and the newer style ('53) u-joint on the slip joint end. A local shop built and balanced it for a tad over $200. It seems to work just fine....