Universal Transmission Co Seattle Washington Under Drive

[1926 T Greg]

Hi I have a complete under drive that was manufactured by Universal Transmission Co of Seattle Washington, it looks as if it has never been installed. The back gear that attaches to the rear end is 10 tooth, any help would be great and if you might have a idea of what it is worth. I already have a Ruckstell in my 1927 roadster and a spare so don't see where I will ever need this.
Thank You
Greg

[DanTreace]

Here is an adv. on the Universal, the TT version, the T would have std. pinion housing as yours.

Don't know value today, but it is complete so someone may make you a good offer, if you place ad in Classifieds.

[Wayne Sheldon]

Universal made several variations of driveshaft mounted auxiliary transmissions for model Ts and TTs. I have had several of them over the years, and really like them.

The underdrives are desirable to some people in the HCCA crowd for early model Ts where they want the advantages of a Ruckstell for hilly driving but want to keep the early axle housings (which the Ruckstell does not fit onto) in their car.

Notice how the "UNDERDRIVE" is letter stamped onto a flat embossment on the main casting. They were designed so that the factory would use the same castings for both over drive and underdrive versions. It is possible however not practical to re-machine parts and convert one to the other. You may want to check to see if someone may have done that to yours? The underdrive was usually around fifty percent, and when turned around becomes nearly a one to two overdrive! That is really tall, and might explain the ten tooth pinion gear on an underdrive housing?

I had a Universal overdrive in the TT I had many years ago. It was about a thirty percent over, and the TT would cruise at about 40 mph. It shifted really easy and I really liked it.

I also had a Universal under-direct-over progressive shift in the original boat-tail roadster model T I had thirty years ago. It was wonderful! The underdrive was about fifty percent, then one neutral, followed through shifting into direct, followed by the second neutral through shifting into overdrive. The overdrive was one turn in, to one and two-thirds out, in other words, a sixty-six percent overdrive! And yes it had a ten tooth pinion on it. That final ratio from engine through the rear end to the wheels was dangerously close to two to one. The only slightly hotter than stock engine pulled the aerodynamic car (boat-tail) on the freeway nicely. Direct with the ten tooth pinion worked nicely almost everywhere else off the freeway.

I did like to joke about how the UDO progressive shift had not just one, but TWO neutrals to get stuck into! However, the fact was, that the gears used an early design constant mesh, and it shifted so easily that putting it into gear was almost always no trouble at all. Although, I do recall once, that the shifting was so easy that on a panic downshift from overdrive at freeway speed, the gear slid right through direct into underdrive. Which actually worked out fine.

The model T coupe I used to have had a Rocky Mountain "six speed" transmission in it. That and the Universal UDO were very similar. I liked both of those.


If your Universal is still an underdrive? Your target market should be the Horseless Carriage Club. If it has been turned around into an overdrive? Someone in the speedster crowd would love it!

[Wayne Sheldon]

One point to add?
The three speed progressives and the two speed under or direct transmissions used different housings.
The TT ad that Dan T posted is for the TT three speed progressive shift version.