42 Chrysler Fluid Drive Fluid

[Guest]

I have a 1942 Chrysler Windsor with fluid drive. I am looking to find out what fluid you put in the converter. Automatic transmission fluid or motor oil? Would appreciate the help.

[johnarthur]

Jim,

I have just noted your request for information re the 42 windsor fluid drive fluid.

I writing from Australia and have found what you want in my service books as I did own a 42 Windsor many years ago.

I assume that being a '42, the engine is a C34, and the oil in the fluid drive should be SAE 20W oil plus 10% sulphur saponifiable base. Exactly what all that means may require you to call your local oil company and ask for the Technical Department and quote the above and I have no doubt that they can decode it for you.

I hope this info helps but I must put a disclaimer on the accuracy as I am only quoting from a book and they have been known to be wrong before.

Best of luck and let me know if you resolve it.

Regards

John A

[Jon Robinson]

Jim:

It was nice of John to write all the way from Australia, and I have an even easier solution for you. I've been driving these cars for over 20 years, and as so many have heard me brag in these forums, I've put 130,000 miles on my 1950 DeSoto in the last 12 years.

Chrysler's Fluid Drive fluid from the 1940s was a low-viscosity mineral oil, meaning that it was designed specifically to NOT lubricate very well so the fluid coupling would grab when the RPM increased. I'm sure this is the reason for the high-tech additive that John's old manual calls for. There are two modern substitutes that have been run for hundreds-of-thousands of miles by me and other Fluid Drive owners, and they'll work just fine because they are exactly what Chrysler's original fluid was.

Use plain old Dextron III transmission fluid, or a big auto or equipment parts store can set you up with tractor fluid. Either will work fine, but as with anything else this old, you might want to fill the Fluid Drive with fresh fluid, run it for a while, drain it, and fill it again just to get all the residue of the previous fluid out.

As for the gearbox on the transmission itself, they originally came calling for 10W motor oil, but 10W is getting a little hard to find, and 30W non-detergent will work just fine. I live in the extremely hot Mojave Desert, and it's a comfort knowing I have a little heavier oil in there. I had a '55 Chrysler years ago, and the power steering called for 10W motor oil, but I found a service bulletin from the '50s saying these power steering units should use 30W oil in hot climates, and I'd bet my bottom dollar there was a similar bulletin for these transmissions in the '40s.

Your '42 was called Vacu-Matic or Simpli-Matic depending on if it was installed in a Chrysler or DeSoto, but I don't remember which was which. As you accelerate, a little oil pump begins putting hydraulic pressure against piston, and when you let off the gas, the piston is allowed to move the gears into High. When you slow down, a cetrifigul switch closes and activates a set of vacuum-operated devices that move the gears back into Low. The vacuum components were replaced after the war with more reliable hydraulic systems, but there's a restoration company out here in California that has restored a friend's '42 DeSoto vacuum mechanism perfectly with the vacuum diaphragms made from modern materials. It's as reliable as the postwar fully-hydraulic versions. I'll get you the name of the shop if you'd like.

The only disadvantage to your prewar transmission are the gear ratios. The gear you start off from a stop in was a bit too high. After the war, that gear was lowered, and they move off with more "umph," but the prewar versions are still great highway cars.

Tell us more about your car. Upload a photo if you have a chance. I'd like to see it.

JON

[Guest]

John and Jon, Thank you for the suggestions. I think we will use the Dextron III. It is the easiest to get. Mixing with other fluids is not a problem because we are installing a rebuilt converter. I use "we" because the car actually belongs to my father in-law. My youngest son and I are helping him get the car going after a few years inactivity due to brakes and a leaky fluid drive. MY son and his fiance are getting married in October (honeymooning in Australia by the way)and they want grandpa and grandma to dirve them in the "old Car" instead of having a limo.

A little history, my father in-law (dad) started working as a mechanic at New York State Electric and Gas in Binghamton, NY after WW2 ended. Every day the janitor came to work in the 42 Chrysler, which he had bought new. Dad fell in love with the car and told the man that he wanted to buy the car when he was done with it. In late 1960's the janitor passed away and his widow sold the car to dad because she new he wanted it. Dad had the engine rebuilt and the body rot repaired and purchased 4 brand new fenders. During the rebuiltd process dad had a heart attack and wasn't sure he would ever get to drive the car again. My wife and I came up to his house and I spent 4 days putting the car back together again and running. The hardest part was getting the cosmolene off the fenders. He drove the car around the block, which calmed him down. Needless to say he got better after bypass surgery. He is now stronger than any of us.

I wanted to attach a picture, but the file is too large If you would like a picture I will be glad to Email you one. My Email address is jsavidge@rochester.rr.com.

Thanks Again !!! Jim Savidge, Rochester, NY