Question on fluid drive coupling?

[MarcDeSoto]

I'm getting my 1948 DeSoto 3 window coupe ready to start for the first time in 30 years!  I have a question about the fluid drive.  I know the ring gear is welded on the outside of the fluid drive housing and the starter turns the fluid drive to start the engine.  Does that mean that the entire fluid drive housing rotates at engine revolution speed when the engine is running?  I know that the clutch is attached to the back of the fluid drive which serves as a flywheel.  So if the fluid drive turns at engine speed powering the impeller, how does the turbine turn at a different speed?  Does the turbine turn independently from the impeller?  I know the answer must be yes, but I don't see how because the fluid drive unit looks like a solid housing.  Also since the clutch has been in the engaged position for all these years, will it be stuck to the fluid drive unit?  And if so, what to do?  Thanks.

[DonaldSmith]

The whole fluid drive housing rotates with engine speed.  

 

The inside is like a bagel cut in two, a hollow bagel, with fins instead of stuff.  Half of the bagel is attached to the flywheel, and half to a shaft to the clutch plate.  At low speeds. there is little force between the halfs.  As speed increases, the fluid exerts an increasing force against the halfs, transferring the power.

 

The clutch is used to change gears.  You can stop at a traffic light without engaging the clutch.  Engage the clutch or put the car in neutral, if like my car there is an odd vibration sound that you may get tired of hearing.  If you are stopped for a long train, put the car in neutral, so as not to overheat the fluid.

 

Now, the transmission behind the fluid coupling and clutch can be a three-speed, like some Dodges, or the four-speed semi-automatic.  With the three-speed, drive around in third gear.    With the semi-automatic, put the selector in the usual three-speed part of the "H", and the car will start in third gear and upshift to fourth. 

Edited December 27, 2014 by DonaldSmith

[_shel_ny]

I'm getting my 1948 DeSoto 3 window coupe ready to start for the first time in 30 years!  I have a question about the fluid drive.  I know the ring gear is welded on the outside of the fluid drive housing and the starter turns the fluid drive to start the engine.  Does that mean that the entire fluid drive housing rotates at engine revolution speed when the engine is running?  I know that the clutch is attached to the back of the fluid drive which serves as a flywheel.  So if the fluid drive turns at engine speed powering the impeller, how does the turbine turn at a different speed?  Does the turbine turn independently from the impeller?  I know the answer must be yes, but I don't see how because the fluid drive unit looks like a solid housing.

 

 

The link that Don C. posted in another thread explains the operation of a fluid coupling.  The one in the link has cooling lines which ours did not have, but the operation is the same.

 

http://p15-d24.com/topic/37666-nice-seeing-our-cars-when-they-were-new/

[_shel_ny]

I'm getting my 1948 DeSoto 3 window coupe ready to start for the first time in 30 years! ............................................................................................................................................................................---  ---------------------------------------------  Also since the clutch has been in the engaged position for all these years, will it be stuck to the fluid drive unit?  And if so, what to do?  Thanks.

 

If you determine it to be stuck you might try checking:

 

http://p15-d24.com/topic/27624-will-clutch-plate-rust-to-flywheel-with-non-use/?hl=%2Bstuck+%2Bclutch#entry275982

 

 

http://p15-d24.com/topic/15703-stuck-clutch/?hl=%2Bstuck+%2Bclutch

 

 

http://p15-d24.com/topic/10680-clutch-does-not-disengage/?hl=%2Bstuck+%2Bclutch#entry92683

 

 

http://p15-d24.com/topic/4581-clutch-problem/?hl=%2Bstuck+%2Bclutch