Here’s a possibility, if your sun and planetary gears are chewed up, your overdrive won’t work. It will be just a 3 speed transmission. No freewheeling.My overdrive section ran low or out of oil and chewed up the gears. Had to get a new gear section off eBay.

  Dennis in Lititz PA

Pintoplumber....you may be right but anyway you look at my problem this transmission is going to have to come out.

Peeeot....I did one final test to confirm that all of the electrical components i.e. relay, governor and solenoid are working correctly.  I hooked up a wire from the solenoid terminal on the relay into the car with a test lamp on the end of the wire.  I grounded the bulb socket and took the car for a test drive and the light came on right at 27 MPH.  I also heard the solenoid click when the light came on.  Do you agree that this pretty much proves that my problem is not electrical but instead mechanical inside the overdrive?

Alan, it definitely sounds like the controls are working like they should.

Do you have a tachometer installed? Regarding freewheeling, I just want to clarify that if you are looking at a tach, when you are freewheeling the tach will drop to idle rpms as soon as you let off the accelerator. If this does not occur (as you have otherwise stated) when the overdrive shift lever is all the way back then there is a mechanical problem. Similarly, if you park the car in any gear other than reverse, without setting the parking brake, and the car holds its position as you would expect with a normal manual transmission, then there is a mechanical problem.

1954 Crestline Victoria 312 4-bbl, 3-speed overdrive

Peeeot....No tachometer, but I parked the car on a slight downward incline with the engine off, put it in first gear, released the emergency brake and the car rolled forward.  Same result in second and third gears.  Only in reverse did the car not roll.  Now I am totally confused!  Thanks again for all of your help.  Alan

Very interesting! So, previously you indicated that you had engine braking below 21MPH. How confident are you that that is the case? Similarly, what tells you that your overdrive is not engaging on the road? Are you able to execute clutchless upshifts? At what speed do you typically shift from 2nd to 3rd? Just trying to get a clearer picture of what you are experiencing.

1954 Crestline Victoria 312 4-bbl, 3-speed overdrive

Peeeot......I will take the car out tomorrow to verify that there is engine braking under 20 MPH as opposed to freewheeling (which I assume I should have if the OD was working correctly).  As to clutchless upshifting, I did not know that this was possible with a working OD so I never tried it.  I would be reluctant to try it as couldn't I end up damaging a gear if it didn't work?  Right now, at least the 1-3 gears work flawlessly and I don't want to mess that up.  This '54 Ford police car that I am currently working on is not my only car equipped with an OD.  I also have a '54 Mercury convertible with the 3 speed OD that I restored and the OD in that car has always worked flawlessly.  When I get up to about 55-60 MPH and back off of the gas, I can feel the Mercury shift into OD and the engine RPM's are reduced.  The police car has never done this.  I get it up to 60 MPH on a straight away and the engine is really revving.  I back off momentarily, and then hit the gas again but the engine is still revving just the same as before I backed off so it feels like the OD did not engage.  Needless to say, I am getting real frustrated with this problem.

Clutchless shifting is possible when the OD is enabled but not engaged. In other words the OD cable is pushed IN but your speed is below the governor cut-in speed. When you let off the gas below the cut-in speed the freewheeling clutch acts as the clutch, allowing you to shift gears. When I do it the stick feels a little stiff compared to a normal shift.

My experience with clutchless shifting matches Dobie’s. 1-2 is easier than 2-3. I usually just use the clutch pedal.

Sounds like you are familiar with normal overdrive behavior from your Mercury, so that definitely helps!

Let us know what you find regarding freewheeling. I think that is critical information in the diagnostic process.

1954 Crestline Victoria 312 4-bbl, 3-speed overdrive

Don't ask me how or why but the OD is now working (sort of).   First, there is now freewheeling in first gear under 27 MPH.  Also, I can do easy clutchless shifting to second and third gears while driving.  Here is how I got it to engage the OD:  I took the car up to 55-60 MPH, let off but no shift into OD.  However, when I hit the kickdown switch and then let off the gas it does shift into OD!   I tried this several times and it worked each time.  Although the trans is not exactly working as it should, I will leave well enough alone as I can at least get the OD to engage.  My only problem now with the trans is an oil leak.  It is not leaking at the solenoid, the speedometer cable or the governor.  It is hard to see where the oil is coming from but the leak looks to be in the area where the OD section bolts to the rest of the transmission.  I tightened the four bolts which attach the OD to the transmission but the leak persists.  Does anyone have a solution short of pulling the transmission and resealing it?  Thanks