Re: [A/S] Re: transmissions & towing

[Jerry Flanders <jflanders2@xxxxxxxx>]

The original overdrive was a separate gearbox, tacked on at the rear of the
transmission. I had one of these - in a Studebaker from about 1950. It
provided a 1.3 ratio stepup to the driveshaft using planetary gears.

I think today's units are simply an additional gear in the transmission,
which the marketing department decided to call "overdrive". I don't know if
they actually step up the gearing, which would require gears to be in-line
and wearing all the time while in OD , or simply a straight-through
coupling, which would be actually preferred for routine driving from the
standpoint of transmission/OD wear.

Jerry