34 Dodge Weard thing

I have came across a thing I have never seen before. It is vacuum operated. Fairly good sized about the size of a modern alternator. It has a 6", 3/8" shaft that comes out and in. It is mounted below the starter motor, close to the clutch and brake arms but it goes no where. What ever it is to control is gone. There is a small lever on the transmission that is wired so it will not move. Could this be a overdrive transmission control? If the car is still there I will try to get you some pictures in a few days.

My guess is that it is the vacuum servo for the automatic clutch. At least it fits the description of the one that is on my '33 Plymouth. They were optional equipment on the upper trim line ("DeLuxe" in the case of Plymouth) for 1933 and 1934 and I suspect also on other makes manufactured by Chrysler.

It is controlled by a knob on the dash connected to a lever on the transmission with another cable/wire from the transmission lever to the the spool valve on the top of the servo mechanism. All the way out on the dash is "locked out", middle position is free wheeling only, all the way in on the dash knob is free wheeling and automatic clutch.

There should also be a rod to the spool valve on the vacuum servo from the cross rod for the accelerator pedal that controls the operation when the dash knob is in the full in position.

Those vacuum servos seem to have been pretty hard to keep running properly and nearly every car I've seen has had them removed. So the number that remain is fairly low and so they can be hard to find by those who want to put their car back to how it came from the factory.

Are you selling it? And you said it came off 34 Dodge ,correct?

Thanks

Steve

Here are some photos of a complete vacuum assisted clutch system on my '32 DL.

Ok I was able to get some pictures. Bonus they had moved some of the junk and I was able to see where the 5/8" rod went. It goes to a lever on the bell housing right where the clutch is. The intake manifold is cast to accommodate the Vacuum line to run this thing. So, ply 33 and phil33dl6 are right it is some kind of a vacuum assisted clutch. All the parts to phil33dl6's unit are there. They are just arranged a little different. That brings us to How do you use it? Currently they are driving the car with out it in operation. Now the transmission. My Motors manual shows a Chrysler type over-drive transmission with the over-drive gear in the transmission not on the tail shaft. Do you think this is one? I have heard stories about a free wheeling over drive transmission could this be one of those? There has to be a reason it is wired into a fixed position. My thought is A. it is broke and the previous owner just disconnected it instead of fixing it. Or B. It is one of those free wheeling over-drives.

Frank

Definitely a '33/'34 style automatic clutch assembly which works with the freewheeling transmission (sorry, not over drive). I'll try to get the '33 Plymouth version's explanation in the owner's manual scanned which describes the operation.

My guess is that the transmission is wired to lock out the freewheeling either due to legal issues (some states banned freewheeling) or because some previous owner wanted it that way. I personally wired mine in the locked out position for a lot of years. I have it so freewheeling works now but I double and triple check that the dash knob has it off when going down a long grade.

Operation is as follows:

1. With dash knob all the way out, automatic clutch is disabled, freewheeling is disabled. Normal clutch operation by driver needed to shift gears in all situations and you have engine braking to help you slow down.

2. With dash knob in the intermediate position, automatic clutch is disabled but freewheeling is enabled. Basically like a bicycle, when you take your foot off the accelerator the car coasts.

3. With dash knob all the way in both automatic clutch and freewheeling are enabled. The automatic clutch is controlled by the accelerator pedal, when you take your foot off the gas the clutch is disengaged. At that point you can freely move the shift lever into any gear (except reverse) without clashing the gears (transmission gears should be stationary or close to it as the freewheeling disengages them from the rear axle and the clutch disengages them from the engine). By putting you foot down on the accelerator the clutch is engaged and away you go.

This was basically an early attempt to make shifting easier. In 1935 Chrysler rolled out synchromesh transmissions and dropped this bit of Rube Goldberg engineering.

Spot on, on all accounts. My transmission was also wired up as in the first picture. A lot of people could not get use to the freewheeling side of things and the cable was disconnected and the transmission wired up.

I even have a photo of a 34 on the showroom floor with the freewheeling cable dragging on the ground ! Not a good selling point if your customers can't control the car.

Great explanation Ply33.

Ian

Overdrive was 1st available in 34 on in the Chry-Desoto line. I'm just touching base for the cars built in the 30s. Dodge and Plymouth had overdrive on the export cars.

I think someone stole mine ...............mine never had one. Wonder why ?

I think someone stole mine ...............mine never had one. Wonder why ?

Was an option?

The automatic clutch servo. Unless it was just an option ?

Yes, Free Wheeling and Automatic Clutch were optional - "Special equipment at slight additional cost". 

So a car without them probably came from the factory that way.