Borg Warner overdrive solenoid

40cpe said:
You can move the lock-out cable while moving PROVIDED the overdrive is not engaged, AND the accelerator is applied enough that the engine is pulling the car.
Click to expand...

Well, dont want to bugger anything up in the transmission so will try it with cable pulled out - when going downhill it should 'engine brake' for me as I understand.
 
You can test the solenoid in the car by attaching a jumper wire of sufficient length to the solenoid terminal on the relay and touching the other end to the hot post on the battery. This eliminates the relay and powers the solenoid directly from the battery. You should hear the solenoid click if it's working. This does not test the pull-in points adjustment but it will confirm if the solenoid windings are OK. The pull-in points must release as soon as the armature extends, leaving only the hold-in points in the circuit. It would be good to remove the cap on the solenoid to check for the presence of oil. Oil inside the solenoid indicates the seal is bad and can cause the windings to short out.
 
Dobie Gillis said:
You can test the solenoid in the car by attaching a jumper wire of sufficient length to the solenoid terminal on the relay and touching the other end to the hot post on the battery. This eliminates the relay and powers the solenoid directly from the battery. You should hear the solenoid click if it's working. This does not test the pull-in points adjustment but it will confirm if the solenoid windings are OK. The pull-in points must release as soon as the armature extends, leaving only the hold-in points in the circuit. It would be good to remove the cap on the solenoid to check for the presence of oil. Oil inside the solenoid indicates the seal is bad and can cause the windings to short out.
Click to expand...
One side of the solenoid is hot at all times so you just need to ground the relay side to test it if i remember right...
 
The operating solenoid provides for "kick in" and for "holding" it in overdrive after kick in so there are two coils in there. The one for kick in has more power in the magnet than the holding coil does so it has to be dropped for holding to make the system more efficient and that requires a set of switch points. The other set of switch points is strictly for a momentary ground of ignition function to allow the holding coil to drop out for a shift out of overdrive gearing. If you pull the cover off, you can see both switches in there and the stuff that makes them work. It's not hard to clean stuff up in there as long as a person is care full not to flood the coils. Electric contact cleaner used carefully will work well and the switch points can be cleaned with abrasive paper or an ignition file. I'm not sure what was used as a lubricant by Borg Warner or whom ever manufactured them but light oil is what I use to keep the works moving well.
 
One thing I have found over the years that causes the BW overdrives to function poorly is the solenoid not getting enough current to kick in. Most problems are with the relay that is mounted on the firewall. When a relays were new you would see the same voltage on the output as what was on the input when the relay was energized. If you bench test an old relay, with it energized, in most cases you will see a large voltage drop between the ign. (input from the ign switch) and the output to the solenoid. The main culprit is at the input fuse holder which is held on by a rivet on each end. When you tighten the screw for the wire terminal that attaches to the fuse holder, it will twist the holder on that rivet and over time will become loose and thus a voltage drop. If you remove the relay cover you will see all connections in the circuit are connected by a similar rivet which can also cause a voltage drop.
The fix to this problem is to clean around all rivet connections and using a good flux, (I use a liquid flux that is used with soldering stain glass), and a good soldering iron, solder the rivet to the surrounding metal. I have done this on many relays and it solved the problem.
Also there could be a voltage drop through your ign. switch due to age and wear so check the voltage from the ign. switch to the relay. It should be the same as the battery.
 
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