Fluid Questions

I have a 1951 Dodge Coronet, with Gyromatic, and I was wondering what fluids to use (oil, transmission, ect..) as the ones listed in the owners manual are not avalable at my local auto parts store. Also I live in Minnesota, and plan on driving in winter, so I can't be running any light weight oils. Can I use good ol' 10W30? Do I have to order something special online? <img src="http://forums.aaca.org/images/graemlins/confused.gif" alt="" />

You should be able to fing 90 weight oil for the transmission and rear end, 10W non-detergent for the fluid unit and I use 30W non-detergent for summer and 20W for winter. All should be readily available...at least I have had no trouble finding the oil.....IF the engine has been rebuilt then some say 20W50 is good

BvR

If your Gyromatic is the same as fluid drive it has separate oil supplies for fluid coupling, transmission and engine.

For the fluid coupling you can use a tractor hydraulic fluid I believe is called "ISO 32". This can be bought quite reasonably at auto supply stores. Originally Chrysler made their own Fluid Drive fluid, this has not been made in years.

The transmission is supposed to use #10 motor oil.

For the engine use 10W30. Detergent oils were available from 1947 on, and your car has probably used it at least from the 60s if not its whole life. Originally they recommended 10W in the winter and 30 in summer so use 10W30 and be covered.

Incidentally in 1951 Chrysler recommended an oil change and grease job every 1000 miles. Modern oils will stand up longer than that, but you should change more frequently than in a new car anyway. The oil filters and air filters they used back then allowed more dirt into the engine and you have to change the oil to get rid of that dirt.

You have to be careful because some Chrysler products used the same oil supply for the engine transmission and torque converter or fluid drive. Yours may be one of these. You can tell them because they have a huge oil pan, it holds 10 or 12 quarts compared to 4 for the normal oil pan.

These models had an oil passage drilled thru the back of the engine into the bellhousing and thence to the transmission.

Addendum to above. The Gyromatic was the same as Fluid Drive and had separate oil supplies to engine, trans and fluid coupling. The one with the combined oil supply was called Gyrotorque Drive.

This info comes from the factory recommendations, and contemporary service manuals.

In my '50 Dodge Wayfarer (3 speed std tranny), I use Dexron II in the fluid drive unit (some recommend not using this but it's been in my fluid drive unit for more than 2 years and no leaks whatsoever), SAE 80-90 in the rear end and tranny (this is not the gyromatic tranny), and 15-40 in the engine. The engine was totally rebuilt and this oil seems to help maintain oil pressure when the engine is fully warmed up. Oil Pressure was very low at idle when fully warmed up using 10W-30.