Overdrive issues

[Tevel Jean-Jacques]

Hello everyone,

While driving my 53' Manhattan to the south of France, I faced major overdrive issue. There are several  symptoms to the problem, and even if I suspect something wrong with the governor or the shift fork switch, I'm far from being comfortable with my diagnostic.

In summary, here are all the issues I noticed.

The problem is intermittent. The overdrive sometime work normally with the gear shifting down and the freewheel working at the deceleration. This looks Ok, except that the gear shift down and the freewheel starts at a lower speed than usual (my OD worked perfectly before the issue appeared).

When the problem appears more severely, the OD does not shift the gear down and the freewheel does not work neither.
When this appends, once I stop the car, it is impossible to engage the reverse gear and the OD manual lock command cannot be actioned.
If I restart the car, the OD works on higher gear and only shifts down if I use the kickdown switch, and this appends on all 3 gears.
The OD can sometime be disengaged by manually actioning the kickdown switch (not really safe when driving I must admit) while moving the car a little bit. This allows to manually lock the OD again and have the possibility to engage the reverse gear.

The only thing I did so far to try to solve the issue is that I replaced the OD relay by a new one, and this did not changed anything to the issue.

Any help you can provide on this issue will be more than greatly appreciated.

Have a great day all.
JJ Tevel

PS: I apologies for not always using the proper words, terms or expressions, but being a Belgian guy and thus with French as mother language doesn't help me in this. I promise I will try to keep improving.....

[Terry T]

appears to be the solenoid, not the relay

[Tevel Jean-Jacques]

Well, I checked both the the solenoid and the relay, and they looks ok. When I manually drive them though the kickdown switch, they seem to work OK...

[Fid]

I had a similar problem.  Does the OD seem to be engaged as you start out from a stop?  If so, the relay is likely sticking.  If the relay sticks, the solenoid will stay engaged and as a result you will not be able to shift into reverse. When I had this problem it was intermittent and replacing the relay fixed it. It's also possible that the wire to the governor switch is worn bare and touching ground somewhere. If this is the case, the relay will remain energized as long as the ignition switch is on.  Take a good look at the wire where it connects to the governor switch and see if it is worn bare.  If so, some electrical tape around it will help.

[Tevel Jean-Jacques]

Thanks Fid for your reply and advises.

As I replaced the relay by a brand new one (I had a spare with me), so I guess that it is working OK, but sure I will check the whole wiring to ensure there is no issue on that. Great idea.

Do you know any way can use to check the governor without taking it out??

[Thomasso]

The governor is an open circuit until it  reaches approx 31 mph and then it goes to ground to complete the circuit.  So the answer is no.  However it is easy to remove and can be spun with a drill or just visually checked.  They rarely fail.

[Tevel Jean-Jacques]

Thank you Thomasso,

I checkas soon as I can and let you know.

[Fid]

I don't know of a way to test the governor switch without taking it out.  One thing I do to test them when they are out is put them in a drill and hold the governor with a vise.  Put an ohm/continuity tester between the terminal and the "case" of the switch.  Power the drill and the ohm meter should drop to 0 ohms when it's up and spinning.  Actually, you can test if it's shorted while it's in the car - do the same thing, ohm meter from terminal to ground - if it measures 0 ohms from terminal to case it is shorted and will cause the relay to fire constantly  hence keeping the OD engaged at all times.