Packard Forum Index » Pre-War (1899-1942)

Has anyone ever converted a non-overdrive 1940 180 to overdrive? I don't have any immediate plans to do this to my car but just curious what is involved and how much $$$$ it would cost.

I converted my 1940 110 to overdrive which I can't image is much different in the basic concept to a senior model.

It required, of course, finding, rebuilding and installing the overdrive transmission and its added supports, cable, wiring, relays, kick-down switch and all the obvious stuff but it also meant shortening the drive shaft and replacing the rear end with the proper ratio for use with overdrive. This latter isn't absolutely necessary but it will make adding it a bit better for highway driving as the non-overdrive rear end was something of a compromise for keeping the RPMs somewhat reasonable at speed but sacrificed the power from a stop. On a junior it made a big difference but maybe not so much on a senior!

This was at least forty-five years ago and cost several thousand dollars but would cost far, far more now especially due to the fact that parts that were difficult to find then will be much harder to locate now!

Are the junior and senior trans and OD units the same? I have a 110 that came with overdrive; eventually I may get it revived.

The 356 engine has a larger clutch plate with a center opening sized for the larger diameter input shaft on the trans -- shaft is approx 3/16" larger than the smaller engines -- and to take the higher engine torque and weight of the car the OD unit has 4 pinions in the OD planetary setup vs 3 used on the ODs for smaller engines. The smaller engines used the same trans and ODs with only the 356 needing the larger unit.

For the original poster asking about converting a 180, if you need a complete setup for the 356 engine you might see if Ross still has this unit available.packardinfo.com/xoops/html/modules/newbb ... .php?post_id=226102#forumpost226102 A complete setup with the electrical etc all in one package offering is kind of scarce.

As Howard (HH56) suggested, the mechanical items are not the same but it is the same system so the conversion would be identical and have the same requirements for any model. You would need to be sure you had senior parts.