1950 Champion overdrive problem

[chrysleritis]

Been a while since I've posted, because the car has been running well (jinx). But the overdrive refuses to engage, so we've just been doing without. With the cable pushed in, you get to the overdrive shift speed, let off the gas pedal, you can hear the relay and solenoid clack, but then the overdrive doesn't fully engage, and you get this horrible gear clash noise. The electrical system seems to be fine -- it passes the checklist, and as far as we can tell, the control cable is adjusted correctly, so that the control lever is fully engaged when the cable is pushed in. It's as if the solenoid armature doesn't have the full throw on it so that the control pawl doesn't engage. We've never removed the solenoid from the unit, and it used to function fine.
Anyone have any suggestion on this?

[chrysleritis]

I guess I'll add that it worked fine until we drained and refilled the oil in the transmission and OD.

[Tom Bredehoft]

I really hate to say this Paul, but it sounds like you need to rebuild your overdrive. It involves removing the transmission. There are some small gears in there, that when they get not enough lubrication, get hot and loose their strength. Then they get literally bent all out of shape.



[img=left]http://www.alink.com/personal/tbredehoft/Bothcars4.jpg[/img=left]
Tom Bredehoft
'53 Commander Coupe
'55 President (6H Y6) State Sedan
(Under Construction) 248 hrs.
'05 Legacy Ltd Wagon
All Indiana built cars

[lstude]

I have the same problem and I also drained the fluid. I had 90 wt oil in it, and it wouldn't go forward in OD, so I switched to 40 wt and it will now go forward, but it makes a terrible noise. I made a video. You can hear the noise as I start off in OD, but you can hear it better at the end of the video.

http://good-times.webshots.com/video/3067676940090795307fdSSzz

Leonard Shepherd

http://leonardshepherd.com/

[Roscomacaw]

Leonard, forgive me, but the way you're saying it here - it doesn't make sense. After you pushed in the OD handle, it sure looked like the car moved frorward some (hard to tell because you had the camera aimed at the dash and floor) THEN you said something about it not going forward and we heard the gears grinding.

Miscreant Studebaker nut in California's central valley.

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe
1957 President two door

[lstude]

quote:Leonard, forgive me, but the way you're saying it here - it doesn't make sense. After you pushed in the OD handle, it sure looked like the car moved frorward some (hard to tell because you had the camera aimed at the dash and floor) THEN you said something about it not going forward and we heard the gears grinding.

Miscreant Studebaker nut in California's central valley.

I guess I was confusing. Before I switched from the 90 wt. oil the car wouldn't go forward in OD, but when I put the 40 wt. oil in it, it would go forward, but made that grinding noise.

Both the transmission and the OD unit is full of oil. I realize that there is something seriously wrong. I have the other OD transmission that I had in the car when I was driving at South Bend. The OD worked fine, but I switched transmissions because the synchronizers were bad.

I guess I have to swap that OD unit to the transmission I have in the car now.


Leonard Shepherd

http://leonardshepherd.com/

[gordr]

What I would recommend that you both do is first to bench-test the solenoid. OD solenoids have a dual-coil electromagnet: a "pull-in" consisting of relatively few turns of heavy wire that draws a lot of juice, and a "hold-in" coil made of many turns of fine wire that pulls relatively little juice. Both coils get their current source from the screw stud on the case. The hold-in coil is direct-wired to ground, but the pull-in coil gets its ground from a pair of switch contacts within the solenoid that are OPENED by a disc on the plunger as it reaches the end of its travel.

To bench test: clamp the solenoid in a vise by one of its mounting ears. Connect the positive terminal of a six-volt car battery to the vise. A battery charger can't supply enough current. Using some good husky test leads, connect an ammeter to the negative terminal, and the other terminal of the ammeter can then be connected to either of the 2 screw on the solenoid. One screw is the grounding terminal for the kickdown, and should be open-circuit with the solenoid un-energized, so it will do nothing. The other terminal should cause the solenoid plunger to pop out about half an inch with a loud thunk. It should move in an eyeblink; the motion should be really forceful. If you were to hold it in your hand, you might be so startled by the force that you'd drop it on your toe, that's why I suggest the vise.

While this is happening, you should see the ammeter kick up to 10 or 20 amps, and then fall back to a low value.

If the pull-in coil is burned out, or not getting a good ground, the plunger will pop out, but it will do so kind of lazily, and the ammeter won't kick up high. If the hold-in coil is open, the solenoid will chatter like a little jackhammer, as the pull-in coil repeatedly cuts itself out, relaxes, and pulls in again. That MIGHT be the noise you are hearing, by the way.

If the solenoid bench-tests OK so far, may as well test the grounding function. Hook a six-volt light bulb between the grounding stud on the solenoid case and battery negative using clip leads. Connect your ammeter lead to the other stud as before. You should see the light come on when the solenoid actuates.

Note: the two internal switches inside the solenoid are not enclosed, other than by the solenoid's outer case. It's entirely possible for them to become dirty, just like the ignition points they resemble. It's also quite possible to remove the guts of the solenoid from the case, and clean those terminals with emery cloth, and to wash any oil/gum from the mechanism with brake cleaner.

If the solenoid checks out good on the bench, it's possible that the balk ring in the overdrive is not gripping the hub of the toothed plate it rides on. A change to lighter oil may have exacerbated that, but I believe using the lighter oil from the get-go is actually the better choice. (The parts wear faster with the heavy oil, but the heavy oil masks the effects of wear better.) In any case, if the balk ring is faulty, the overdrive will have to be disassembled.

I recommend the solenoid bench-test first, because it's easy to do, and doesn't cost you anything except a little time. And if you do find a fault with the solenoid, you may avoid an unnecessary tear-down of the overdrive.

Hope this helps.

Gord Richmond, within Weasel range of the Alberta Badlands

[chrysleritis]

So it was finally winter vacation before I began seriously on this problem. I just kept the car off the highway until I could get to it. And the in-laws were in town, so I needed a large project to keep me in the garage. Pulled the transmission off the car, and of course dropped in on my hand while under there. Which is good, because you wouldn't want to ding the case having it hit the hard floor, right? Anyhoo, on disassembly, the overdrive was a total mess. Chewed gears. Surprising that it still rolled at all. I found a unit from a Willis on ebay going pretty cheap (cheaper than getting the gears and shafts one by one), and it contained a really nice pinion and cage assembly for the overdrive. It was a bad job pulling everything apart with badly bent gears. I am part way through the reassembly, waiting for a couple of new snap rings. The cases are resplendent in new green paint. A good learning experience, overall. Now -- do I replace the clutch while I have the transmission off?

[Aero Blue]

chrysleritis, have you read the Lubrication specs on page 195 & 6 of the 1950 Shop Manual? You need to use a "mineral" based oil (S.A.E. 90) or 40 weight engine oil. Studebaker warned about using extreme pressure oils. Mineral based oils can sometimes be found at farm and tractor supply stores as many of the old tractors still use them

[Studeman]

What I have used since 1983: Was recommended to me by a very LOOOOONG time Studebaker oowner/driver/mechanic...

30 Wt NON-DETERGENT motor oil, mixed 50:50 w/STP oil Treatment.

2 Quarts oil, 4 Pints STP (makes 1-gallon)

This is enough to completely fill the Transmission AND the Overdrive (fill them each seperately). There is also enough left over for topping off if you have a leak or someting.

Ray


Specializing in Studebaker Restoration