Oil for Hydraulic Shift Transmission, 1950 Desoto with Fluid drive

[Indian 101]

What kind of oil should I use for my hydraulicall operated transmission in my 1950 Desoto. The warning on the transmission (see pictures) says 10-W motor oil,  but I can`t find that type of oil here i Norway. Anyone who can advise me on a more common oil that works in this transmission?

 

[Spinneyhill]

10W motor oil is at the lower end of the 75W gear oil viscosity range.

Oil-Viscosity-Comparison-Chart.pdf

 

If you use a 75W gear oil, you must think about  the gearbox metals. If there is any yellow metal (ie. containing copper) the gear oil must have a 1a (or 1b) result in the Copper Strip Corrosion Test ASTM D130, ISO 2160: 1998. I would imagine the baulking rings (a.k.a. synchroniser rings) are bronze. If you can't find those results, look for another oil. The MSDS (or SDS) often has these results within.

 

Having said all that, I am not familiar with those gearboxes, so this is just a bit of info. about oil and may not relate to your gearbox.

[Rusty_OToole]

We use tractor fluid, TDH type, ISO22 or ISO32 grade. TDH stands for transmission, differential and hydraulic oil. We get it at auto parts stores or farm supply stores. Any place that sells oil and grease for cars, trucks and tractors should have it.

It may also  be called Universal Tractor Fluid or Transmission and Hydraulic Fluid depending what brand it is.

It can be used in the transmission and in the Fluid Drive. They are filled separately.

One 3.78L container should be more than enough to top up the Fluid Drive, and change the transmission fluid.

 

 

Edited December 22, 2017 by Rusty_OToole (see edit history)

[Indian 101]

thanks!

I don`t think I need to exchange the oil in the fluid drive assembly, but is it correct that you use the same oil here and in the transmission case itself (TDH, ISO22 or ISO32)?

[Rusty_OToole]

Yes. Fluid Drive unit and transmission use the same oil, although they are separate. If you do a search for Fluid Drive in the Chrysler section you will find plenty of information. The care and operation of this transmission was gone into very thoroughly in a couple of long threads in 2008. I have personally answered these questions more than 100 times. Please take advantage of the search function.

 

The DeSoto transmission is identical to the Chrysler. The same setup was used by Chrysler, DeSoto, and Dodge cars. They gave them different names but they are the same.

 

Chrysler has no recommendation to change the fluid in the Fluid Drive unit, they recommend changing transmission oil every 10,000 miles (16,000 Km).