Borg Warner OD not working once hot.

R

rjlester

Senior Member
Car is a 1954 Meteor with the factory Borg Warner Overdrive that most of the time works fine.

For a few years I've had the OD (on rare occasions) not engage once the car has been driven for a while. Usually it takes a few hours of driving or more. Then once it sits overnight, it works fine the next day, and the problem sometimes won't come back for months! Well, yesterday I put about 300 miles on the car. I was about 20 minutes from home and it stopped working. I think maybe the solenoid is sticking, my volt gauge shows a big battery drain, and was around 6.1 volts. If you engage the kickdown switch, the voltage will jump to just over 7 volts. I have tried my spare solenoids in the past and as far as I remember, they all did the same thing. This morning we drove the car to town, and on the way home, it failed about 5 minutes from home.

Whats weird is, it never failed for probably a year until last fall. It was fine after that until yesterday.

Another strange thing that has showed up in the last year or so, is if I make a right turn, and slow down to about 5mph in first, the OD is sometimes still engaged when I shift back to second gear.

Last fall I took the governor apart and it looks like new inside, makes a perfect connection according to my ohmmeter.

Any ideas? The wiring connections are all clean, and the kickdown switch is new. It has never blown the fuse.
 
A similar problem I used to have with my BW overdrive was transmission oil was getting past the solenoid plunger shaft seal and getting on the contact points causing them not to make contact not allowing it to shift into OD. I removed the solenoid and took the case apart, cleaned the contact points and she started working again. Don't know if this is helpful, but it's the first thing I thought about when you described your problem.
 
You know that's not a bad idea. I can take the cap off an have a look. There is a new seal in there, but there is oil coming from elsewhere (outside of trans is a bit wet with oil) and may have contaminated the contacts.
 
The solenoid has two sets of contacts. One is for drop out to restore ignition function during kickdown and the other is for the change over from the push in coil actuation to the holding coil action during shifts into overdrive. The holding coil uses a lot less current than the actuating coil.

If oil is leaking in there then the little seal must be replaced.
 
I finally got around to pulling the cap off the solenoid. It was bone dry in there. I ran sandpaper through both sets of points, and cleaned the two wire connections. No corrosion was visible, and definitely no oil. Will see how it behaves on the next long drive on a warm day.
 
Another thing that you can do to help improve the operation of the overdrive system is easy to do. Add a ground strap…..from one of the bolts holding the solenoid to the transmission casting…..connected to the steel body at a nearby location. Don’t connect to the frame. This will provide a best possible ground for the overdrive system. Both the solenoid and the governor are ordinarily grounded through the transmission case. If the quality of the ground has degraded over the years, the operation of the overdrive system is affected. Both of those components must get a good ground and that occurs through the transmission castings….through the bell housing….through the engine block….and through the ground strap connection to the firewall (the body of the car). There are many disruptions to this path, such as dirt, paint, oil, loose fasteners, etc that can develop over all the years. Adding a ground strap can only help the quality of the ground for the overdrive system.

Make sure to use a sufficient gauge of wire and make it long enough to allow for some flexible movement. I like to use stainless steel hardware for the ground strap including stainless steel tooth washers. The connection to the body needs good clean metal to metal contact. A dab of silicone sealer over the new tight connection helps keep it clean and free of any eventual corrosion.
 
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My 50 did almost the same thing what I found was generator was charging but not enough rebuild the generator and brought the voltage up to I believe it was @ 7 volts at 1500 rpm problem solved good luck
 
Mac VP said:
Another thing that you can do to help improve the operation of the overdrive system is easy to do. Add a ground strap…..from one of the bolts holding the solenoid to the transmission casting…..connected to the steel body at a nearby location. Don’t connect to the frame. This will provide a best possible ground for the overdrive system. Both the solenoid and the governor are ordinarily grounded through the transmission case. If the quality of the ground has degraded over the years, the operation of the overdrive system is affected. Both of those components must get a good ground and that occurs through the transmission castings….through the bell housing….through the engine block….and through the ground strap connection to the firewall (the body of the car). There are many disruptions to this path, such as dirt, paint, oil, loose fasteners, etc that can develop over all the years. Adding a ground strap can only help the quality of the ground for the overdrive system.

Make sure to use a sufficient gauge of wire and make it long enough to allow for some flexible movement. I like to use stainless steel hardware for the ground strap including stainless steel tooth washers. The connection to the body needs good clean metal to metal contact. A dab of silicone sealer over the new tight connection helps keep it clean and free of any eventual corrosion.
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This is very good advise. Sometime in the future I will add a better ground as suggested.
 
joe 1950 said:
My 50 did almost the same thing what I found was generator was charging but not enough rebuild the generator and brought the voltage up to I believe it was @ 7 volts at 1500 rpm problem solved good luck
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Yes, when this problem showed up a few years ago, I chased what I thought was a charging system problem, but mine is charging very strong like yours. As soon as I pull the fuse for the OD (when its having this problem) the voltage jumps back up over 7 volts. I installed a voltmeter in the glovebox and it's great for monitoring things!

I did take the car for a relatively long drive the other night and I have zero issues to report. If anything, it almost feels like it shifts into OD smoother, but likely just my imagination.
 
Just to add to my previous comment, don’t do anything to seal up between the overdrive adapter and the solenoid body…….ie adding a gasket or spreading some sealer around the surface. Keep it as clean metal to metal contact, and that includes the two bolts. If it’s been leaking oil in this area you’ll need to replace the little oil seal in the adapter.
 
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