Technical Overdrive solenoid question

Hey all...finally had a guy look at all my electrical for my overdrive as to why it was intermittently working and now not working at all...... he checked /cleaned all connections and tested voltages and I have power everywhere. He said he did find that when he grounds the overdrive solenoid that the arm won't fully push in unless he helps it just a little. He seems to think this is my problem.....

Any thoughts? Can I have the solenoid rebuilt or just buy a new one? Thanks

 

Take it apart & clean everything. It's got 65 years' worth of oil/dirt/corrosion inside, & they come apart for service. Points will need to be filed, & you can do the same with the relay while you're at it.

 

Make sure you have the right voltage solenoid; a 12V solenoid will be 'lazy' on 6V....

 

Thanks for the advice....gonna have to read up on filing the points.... not sure if that's something over my head or not...but worth a shot

 

You can do it, just take the 2 nuts of the solenoid cover and remove it you will see 2 sets of points inside just run some sand paper thru them and replace the cover. ground the solenoid and with a jumper off battery touch the wire connections and it should snap out. Too remove it from transmission take the 2 bolts out and then twist it about 1/4 turn and it will come out. no oil will come out. when repaired put it in and then turn it the 1/4 turn and bolt it back in. one set of points is to engage it and the other is to hold it in. LOL.

 

Hamber VanPelt http://www.vanpeltsales.com/ is a basic source of parts and information for this rig.
Some parts like solenoids have gotten scarce...this place http://www.fifthaveinternetgarage.com/overdrive_parts.php has repros, at a price...

 

Before pulling the solenoid, pull the cable to lock it out of OD ...

 

This guy is claiming he built the first 6V car alternator which is nonsense.... They have been around since the 40s, just not as 'typical' equipment. I knew a guy in the late 60s that had a unrestored ex-Seattle FD chiefs car (a '47 Chev Fastback) with a 6V alternator. Somewhat crude by todays standards, the stator/rotor assembly was the size of a coffee can and the separate rectifier/heat sink was as big as a toaster (and got nearly as hot under load). IIRC, it was made by Leece-Neville, and the only place you found them was on industrial equipment and emergency vehicles.

 

Great information here Bruce! Thanks for posting this!

 

I had a similar problem with my 6V OD. It would work OK for a while and then wouldn't engage.
Tried another solenoid, better ground, etc., nothing worked. Turned out to be the voltage regulator was bad. New voltage regulator fixed it.

 

Actually, one set of points is normally closed and then opens when the shaft throws--- this disconnects the main magnetic coil and leaves the secondary magnetic coil energized. The second set of points is for the kickdown, it is normally open until the solenoid throws--- this is the "engine killer" switch that grounds out the ignition coil until the solenoid retracts.

As far as the OP, I know you said that the solenoid is getting fed, but have your electrician check the voltage getting to the solenoid-- sometimes the voltage will be fine when you first start up until you drive a awhile or have the headlights on. If the voltage is low, then the solenoid will try to throw, but be unable.

 

Thanks Mike51Merc....I am getting 6.4 or so the solenoid....

 

I'd suggest bench testing the solenoid. It's easy to remove and you can see easily see how it performs. If it is hesitating on the workbench, it's gonna be useless in the transmission and at least you'll have found your problem, if it performs well, then you gotta trace the system backwards. You should open the can of the OD relay and examine/clean/adjust the contacts inside and make sure it is activating properly. Another place to examine is the kickdown switch because its location exposes it to a lot of road grime and moisture. A new kickdown switch is only about $35.

Another trick is that on the Merc the heavy wire on your voltage regulator is right near the SOL terminal of the OD relay. This is a great place to wire a jumper switch with wires running under your dash to create a "manual override" to send power directly to the solenoid. If you do this, when the switch is on OD will be engaged full time regardless of speed. Beware to never attempt driving in reverse with OD engaged, very bad things can happen.