Fluid drive revisited

[Hickory]

.My car is a 49 Chrysler royal. At a stop I have to use the clutch pedal. I've been using the car as a standard due to the fluid coupling appears not to de couple. The idle is set at 450 rpms. I've tried higher and lower rpms. Fluid level is good and when I had the tranny out there were no leaks and it rotated free.

[keithb7]

Explain a little further.... At a stop light if you don’t use the clutch what happens? Engine stalls?

[Hickory]

Yes, engine stalls. The engine and tranny have both been rebuilt and operates as designed.

[Dodgeb4ya]

So ...

At a complete stop in low or high range ,

clutch pushed in, engine idling smoothly..brakes applied

If you let the clutch pedal out...it will immediately kill the engine like on a regular standard transmission car?

[keithb7]

Certainly an interesting problem. I am a little stumped and look forward to learning the answer. 

 

Thinking about the throttle wiring that cuts power to the coil temporarily when forcing a downshift to 3rd. I wonder if it could be somehow related to the indicated problem?

[Hickory]

Low, high or even reverse. If I lower the idle down to around 380 rpms it starts to release but engine dies out due to load at a low idle. I was wondering if the fluid was to thick if it may keep coupled at lower rpms

[Dodgeb4ya]

Idle needs to be at 450 to 500 rpm.

[Hickory]

It's at 450

[Worden18]

Idle is set at 600 on my car.  When I "use" Fluid Drive at a stop sign it idles down to 450rpms.  Set your idle up a bit and retest?  Just my opinion.

[Dodgeb4ya]

20 minutes ago, Worden18 said:

Idle is set at 600 on my car.  When I "use" Fluid Drive at a stop sign it idles down to 450rpms.  Set your idle up a bit and retest?  Just my opinion.

I agree set it to 500-600... should idle smooth and not die.

It's either an engine tune up issue or the fluid coupling possibly could be locked up because of a internal front bearing seized up or damaged vanes.

Never seen either issue except on a Fluid torque drive converter coupling.

Oil too thick maybe?  but would be very hard to fill one up with thick oil. The fill hole is only 3/8" in diameter! 8 quarts to fill it

Edited November 3, 2019 by Dodgeb4ya

[Hickory]

I've tried the rpms at 450, 500, 550, different timing. I just rebuilt the engine and has fresh tune up. Runs great. Not a runnability thing. When the fluid coupler was on the bench it rotated freely and smooth. Has me stumped. I can only think of oil issue.

[Worden18]

1 hour ago, Hickory said:

I've tried the rpms at 450, 500, 550, different timing. I just rebuilt the engine and has fresh tune up. Runs great. Not a runnability thing. When the fluid coupler was on the bench it rotated freely and smooth. Has me stumped. I can only think of oil issue.

What type of oil did you use?

[Frank Elder]

If you have the wrong fluid and it causes foam the pump will cavitate and not function properly.

[Hickory]

I haven't changed the oil.

[Dodgeb4ya]

Very odd  issue if you let the clutch out and the engine just shuts off you will not like re filling that FD coupling?

[Doug&Deb]

The Imperial website has a troubleshooting manual available for download. I recommend going through this procedure. My Coronet was doing the same thing. It turned out to be bad wiring to the governor and solenoid . A new harness fixed the problem. The M6 can be finicky but once sorted it’s pretty trouble free. Good luck.

[Hickory]

It is odd, I can start the car in gear and take right off. And it baffled me since the clutch surface rotated so freely

[greg g]

What transmission is in the car?  Guess we are assuming it's a semi auto.?   How long has this been occuring?  Was there a problem before you had the trans out?

 

When we were kids we used the tree test to verify fluid drive was working.  Put the front bumper against a stout tree. Rev it to about 6-800 rpm, place the gear selector in high range or high gear.let out the clutch.  Does the car stall?  If yes it's not fluid drive or the fluid drive unit ain't working right.

[Adam H P15 D30]

My 49 Dodge behaves the same way, started about a year ago.  I have been contemplating changing the fluid in the coupling but it doesn't leak so I really don't want to mess with it.  Just been driving it like a normal 3 speed but sooner or later I want my FD back.

Have you checked the fluid level/condition?  Could be like mud, who knows...  Hmmm, I think I'll check mine this weekend

James Douglas has done extensive research and testing with the FD, he probably knows more about them than anyone else here.

I read somewhere thicker circulating oil makes it slip more???  I would think the opposite is true.

Thinking of filling mine with transmission fluid with NO seal additive and check, that would be about 7.5w.  If I kill it, I've got a 440 sitting around, or just change it to a clutch and be done with it, who knows? 

Sorry, just thinking out loud.  When it was working normally, it sure made it fun to drive...

 

[Merle Coggins]

I had a similar issue several years back. I couldn't hold my truck against the FD at idle without the engine dying. If I turned the idle up high enough it wouldn't die, but it was hard to drive that way. After a good tune-up, including a carburetor adjustment, it now runs much better and I can use the FD as it was designed.

[chrysler1941]

14 minutes ago, Merle Coggins said:

I had a similar issue several years back. I couldn't hold my truck against the FD at idle without the engine dying. If I turned the idle up high enough it wouldn't die, but it was hard to drive that way. After a good tune-up, including a carburetor adjustment, it now runs much better and I can use the FD as it was designed.

Also mine several years ago. Tried everything. Solution was adjusting idle to run a bit rich. 

Edited November 4, 2019 by chrysler1941

[Phil Martin]

Mine will die like that     but not immediatly it will just idle down the die. Too high idle and it doesn't want to shift up. Runs great other than that. M6 trans.

[Hickory]

M6 trans and its hard to hold back with brakes. Everything is stock and has done it since I got the car. This will be a winter project as it's below freezing as of this morning an now won't leave the garage.

[James_Douglas]

Two things to check. First, make sure the oil level is correct. I have seen people fill it on the bench and over fill it. Not good. It should be checked in the car, COLD, via the hole in the floor board. That hole is in the correct spot to fill the thing to the correct level. The second thing is to use the correct fluid. Not ATF not this and not that.  Go read my write up and use the correct fluid.

 

One last thing. Some people placed BOLTS in place of the fill plug that turns the fluid coupling into a big flywheel, I carry one such bolt on road trips just in case the coupling fails as one can put the bolt in and drive it like a stick.

 

James

[Hickory]

I would have to say no to the bolt thing as it sounds freely and smooth when I had it out of the car