'48 Windsor Fluid Drive draining proceedure

[Guest markrush]

I've spent about an hour reading old posts and I want to make sure I know what I'm doing before I start servicing the fluid drive. I have a C38 '48 Windsor 6cyl 4-dr sedan. Correct me if I'm wrong, but I understand I remove the plate on the right side of the transmission hump. Then I open up the plate and key the starter (or do I turn by hand) until I see a plug. Then I remove the plug and check the oil with my finger. Now, what if I want to drain all old fluid and replace with fresh? Do I rotate the open plug to 6 o'clock like some threads have suggested? If so do I use the key/starter or do turn it by hand? Where does this drain out? I do have a suction gizmo, but I think more crud is removed by gravity draining. I guess I then return it to the upright position opposite the cover and fill with a funnel?

[c49er]

Please post a picture of the crud that comes out so we and others will understand a Fluid Drive drain and fill.

[Rusty_OToole]

Chrysler did not recommend draining or changing the fluid in a Fluid Drive unit. They said it was a sealed unit with no way for dirt to get in and there was so little air the fluid did not even oxidize.

However I doubt they planned on them lasting this long. If you want to change the fluid here is how I would do it. Look under the car, there should be a removable plate on the bottom of the bellhousing. Turn the flywheel with a pry bar or have someone bump the starter until the plug is at the bottom. Remove plug and let drain. Replace the plug and bump the starter until the plug comes into view through the access plate under the dash.

It is best to remove the coil wire so the motor can`t accidentally start.

The access plate is on the passenger side of the driveshaft tunnel below the dashboard. Roll back the carpet and you will see it. Take out the screws and set the plate aside. You will see a round plug on the bellhousing, pry it out and you will see the fluid drive. Bump the starter until the plug comes in view. Stuff a rag around the hole so you can`t drop the plug, and remove the plug. Fill the Fluid Drive unit with a funnel. This will take some time as the fluid goes in slowly.

Fluid Drive fluid no longer available, use 10W motor oil or TDH tractor fluid, ISO 22 grade. If you can`t get ISO 22 get ISO 32.

When the Fluid Drive unit is full put the plug back in remove the rag, replace the plug in the bellhousing put the cover plate back on and replace the carpet.

[Guest markrush]

Thanks for the help. The only plate I saw on the underside of the fluid drive was a small (c. 1'') round plug on the very bottom. It had two small square markings on it. It didn't look easy to get out (or back in without damage) so I left it alone. I ended up just topping the fluid off. It only took 2-3 ounces. The only other opening was a ventilator with a screen on it. It was held on with brad-like fasteners without screwdriver threads. Should I have drained it through there? It seemed like it would leave a bit of a mess that would attract dirt.

[Rusty_OToole]

According to the factory you are not supposed to drain them at all. So no wonder they didn't make provision for easy oil changes.

Have not looked under a 48 Chrysler but most cars have some kind of removable cover down there.

I think you did the right thing. If it only took a few ounces then your fluid drive unit is in good shape and the seal is not leaking.

[Guest markrush]

I have since found a statement in a 1948 Chilton manual which talks about filling while removing and overhauling the fluid drive. It says, in part, "Fill the unit with fluid drive oil, free from dirt, until the fluid just spills from the filler plug hole. " I did that, but then it says, "Replace the filler plug, using a new gasket, and tighten securely. Tap the wrench with a hammer to make sure that the plug is tight." I don't think there was a gasket. Should there be? Would it be a rubber , copper, or what? I sure don't want that fluid flying out.

[Rusty_OToole]

I have since found a statement in a 1948 Chilton manual which talks about filling while removing and overhauling the fluid drive. It says, in part, "Fill the unit with fluid drive oil, free from dirt, until the fluid just spills from the filler plug hole. " I did that, but then it says, "Replace the filler plug, using a new gasket, and tighten securely. Tap the wrench with a hammer to make sure that the plug is tight." I don't think there was a gasket. Should there be? Would it be a rubber , copper, or what? I sure don't want that fluid flying out.

I believe the original seal was a copper gasket. You would not see it if it was stuck to the plug as they usually are. If you followed my advice about the rag you would have seen it if it fell off.

A copper drain plug gasket will wear out after being reused 5 or 6 times. So your car will need a new one around 2050.

Don't worry about it unless you see a big puddle of oil under the car.