Hot Rods Need 3 speed stick/overdrive info.

I need some information from the overdrive savvy members.
I have a '51 Chevy, converted to an open drive line.
It is a '61 235, see avatar, with a Borg Warner 1959 Chevy 3 speed stick/overdrive and a Ford 9", with 3:50 positraction.
The "Tee Handle" assembly for the overdrive is also from the same 1959 Chevy.
The normally found overdrive electric carb. switch is not on the dual carbs, instead, the overdrive activation switch is a "toggle" mounted under the dash.
I know ZERO about these Borg Warner units.
The "Tee Handle" operates, as it would on any '55 and up passenger car. "Out" position for disengagement, "in" position for engagement.
MY question and concern is this, looking for direction from any overdrive guy.
With a 2:94 first gear ratio, in the "lock out" mode, and the 3:50 rear, I would think the car would accelerate relatively well, but the car accelerates like a snail, almost like starting off in 2nd gear.
If the electrical toggle switch to the solenoid remains in the "activated position", will the transmission stay in the overdrive mode, regardless of the Tee Handle position?
First gear is a 2:94 ratio in non overdrive mode, but the first gear ratio is a 2:058, in the overdrive mode.
It certainly feels like it's in the 2:058 overdrive ratio, on initial acceleration.
Any and all help is appreciated.
Thanks.

 

I'm hoping someone out there can help, with this concern.
Thanks.

 

In your case the answer is maybe. I don't believe the tranny will go into OD unless the cable is first pushed in. However your set up is not like the factory and may not work as original equipment.

The toggle switch, I assume, energizes the solenoid. With the cable pushed "in" the tranny will go into OD. On the factory set up, a governor on the tranny tailhousing acts as your toggle and will "cut off" the power to the solenoid when the car is below 35 mph. You may need to either pull out the cable or turn off the toggle when you come to a stop.

 

Bob,

I think I would start by ensuring the 'lockout' lever is correctly oriented on the trans and the OD is locked out when T handle cable is pulled out. If that were operating opposite expectation, it would be engaging the OD when it is thought to be disengaged.

As I understand it's function, the solenoid disengages the OD 'on demand' when the vehicle is being operated in overdrive. In the factory setup, the throttle linkage has a momentary switch whose plunger is pressed when the throttle is fully opened. That switch triggers a relay that does two things.....it momentarily disrupts the ignition circuit so the engine 'unloads' the drive line and simultaneously actuates the solenoid and that disengages the OD.

So, I think your solenoid is likely not the cause of your problem, because even if actuated full time via the toggle switch, the solenoid engagement would, or should, prevent OD engagement. You would have the opposite problem.

Are you sure the lower than expected performance is solely related to the transmission swap? Was the engine (vehicle) performance meeting your expectations before the trans was swapped? Rereading your post, I am unclear if both the 9" rear axle and transmission were installed at the same time, or if you had the 9" in place with a non-OD trans in operation before swapping in the OD unit. Where I am going is this: to what prior driveline configuration are you comparing present performance? I tend to think you have a lower numerical rear axle ratio (3.50) than what the car was originally equipped with (3.70/3.90/4.10).

Ray

 

I forgot about the governor until I read '57 HEAP's post. It may be possible the governor is not functioning, 'stuck' in one position, and is affecting the OD operation. However, I would still tend to think the OD would be locked out if the cable/lever are in lockout position. But it would still be worthwhile to remove and inspect the governor operation.

Ray

 

Pulling the handle out disables the OD completely. It becomes a std 3 sp. There is a govenor that is supposed to prevent OD below 30 MPH. There are strange things with an OD. With the handle in, the car can roll back if not in reverse. Always put the car in reverse when parked.
If the handle is in and there is power to the solinoid, it may be in OD. I forget if continous power is put on the solinoid.
It would be interesting to see if the car will roll back in gear with the handle out. If so, pulling the OD unit and inspecting, cleaning might be a good idea.
Pulling the solinoid might tell you something. The solinoid pushes a bar that inables the OD. If somehow it was stuck in, the OD would be ingaged. The solinod is turned 90* to get it off.

 

YES. The OD has to be OUT of OD to be manually locked out with the cable, and if the governor has been bypassed (and it sounds like it has), any time the 'manual' switch is 'on' the trans will engage OD regardless of vehicle speed. The governor operates the OD at slower speeds in original configuration, preventing its engagement when accelerating until you reach about 27 mph, disengaging it when you drop below about 21 mph. These speeds would be a bit higher because of your taller rear gears.

With a 'manual' setup like this, YOU have to manually shift it in and out of overdrive using both the switch AND the clutch. Shifting it without the clutch can damage the OD shift pawl, as can pulling the tee handle out when OD is engaged. This mod was popular at one time because this allowed you to 'split' each gear, giving a faux 6-speed but requires the operator to manually perform all shifts if the governor was bypassed.

To 'split-shift' the trans when set up like this, with the tee handle IN (OD mechanically enabled), to take off from a stop, with the clutch in turn the switch 'off'. Accelerate, then push in the clutch. With the clutch in, activate the switch. OD will engage, let the clutch out and accelerate again. When shifting to 2nd, again turn the switch 'off' while the clutch is in, this will give you 'low 2nd'. Accelerate, push in the clutch and turn the switch back on, let out the clutch and you'll be in 2nd high. Repeat for third gear. When coming to a stop, push in the clutch and turn the switch to 'off' to disengage OD.

To operate the trans 'normally', keep the OD cable 'in' and the OD switch 'off' until you reach cruising speed. Then push in the clutch, turn the switch 'on', wait for OD to engage, then let the clutch out.

I will note that a 3.5 rear gear is rather tall for a OD unit. That makes your rear gear an effective 2.45 when OD is engaged. Typical rear axle ratios were usually 4.1 or 3.9, on a lightweight V8 car you may see a 3.7.

 

so, Steve.........reading your post suggests the solenoid is instrumental to OD operation in both 'relaxed' and 'activated' position. I admit no real authority on this topic, though I have owned, and now own, OD equipped vehicles. That said, my 'impression' has always been the solenoid was used actively to disengage the OD and was passive in the ordinary engagement of overdrive. Stated another way, wouldn't the OD operate as an OD with the cable 'in', and a properly operating governor, even if the solenoid had no wires whatsoever attached? In that configuration, only solenoid disengagement being affected?

Is that an incorrect notion? Guess I'm going to have to dig into the shop manuals.

Ray

 

Ray, off the top of my head I can't remember if the solenoid engages or disengages OD when energized, but it HAS to be functioning to 'shift' in or out of OD. The governor is what operates it under 'normal' electrical circuitry and that has no mechanical connection to the OD.

'Back in the day', this mod was normally done by simply 'moving' the kickdown switch from under the gas pedal to the steering column or shift lever, leaving the governor and kickdown relay in place. That doesn't seem to be the case here, with both of these items being missing or not connected (which is why I suggest using the clutch when 'shifting' in or out of OD). If the only control on the solenoid is the manual switch, leaving the switch in one position will 'lock' the trans either in or out of OD. The trans HAS to be out of OD for the cable to be able to lock it out.

 

At least on my ford b/w od's, the solenoid has two coils. One is a high amp to pull in, and when it moves all the way, the "pull" in coil disengages, and a lower amp "hold in" coil takes over. The sw is inside the solenoid. If the hold in coil fails, the od tries to pop in and out on the test bench. Using the pull in coil full time will cook it. And the solenoid will get very hot before it burns up. Been there.

The solenoid has to rotate to install or remove. If it was installed without being rotated ( you can feel it enter a slot on the pawl, after you rotate it if you pull, it won't come out), it may engage the pawl inside the o/d unit. Usually, backing up with the o/d engaged will lunch the internals, but my foggy memory tells me some set ups had an internal rod that disengaged the o/d when the reverse gear engaged. Foggy being the operative word.

I'd pull the solenoid first to check for proper installation. Then bench check the coils while it was out.

 

As I said, I know ZERO about the Borg Warner O.D., or any other O.D., as I think about it.
This '51 came to me, through an estate sale of my late friend.
I have not done any of the mods., it is, as it was, when I became its' caretaker.
1961 235 (see avatar pic), 1959 Chevy B.W. 3 speed stick/O.D., Ford 9" with 3:50 positraction.
I have a book full of receipts, all info is documented with the associated receipts.
Looking at the avatar, you can see the detail in my friends work, the undercarriage is as crisp and clean, as the engine bay.
Thanks to 57 Heap, Hnstray Ray, Andy, Crazy Steve and Miker 98038 for the comments and ideas.
I'll need to poke around, with these ideas, my thinking is that it's stuck in O.D., based on its performance.
I may decide to remove the overdrive, in favor of a basic three speed, stick, if it gets too convoluted for this ole guy.

 

To defeat the OD, simply disconnect the electrical connections at the solenoid at the transmission ('safe' the ends) then pull the OD tee handle out and leave it there. That locks the OD out, you now have a plain 3 speed.

 

If your driving the car and its shifting, going into reverse, etc. the o/d probably isn't lunched. You might try over on the ford barn.com, this subject seems to come up a lot, since I think more fords used the b/w unit, R-10 light trans,and R-11 behind the T-85. Even with the 3:50 rear, they're really nice when their right.

Back in the old days, for the ford guys, you went looking for a 6 cyl o/d wagon, 1955 or 56. They had a 4:27 Dana 44 rear end, and would interchange car or bird. Really nice combo with the o/d.

 

The govenor keeps the OD from engaging below 30 mph or so. If the OD is engaged in first when taking off then the govenor was been bypassed or is malfunctioning.

 

No. If the solenoid doesn't engage, the tranny will freewheel with the cable "in". The car will move, but the engine will slow when the throttle is let off. Then when re applied, the engine will speed up until it pushes the car.

 

All the above remarks are correct, but since the OP didn't mention freewheeling, that's why I suspect the solenoid wasn't correctly installed. I remember using a jumper wire to "energize" mine on the T-85 to put it back in. That was back in 68 or so, like I said, foggy memories.

 

EZ, I did not understand your comment.

 

I edited my post. Maybe it makes sense now.

 

Ah yes, now it is clear. Thanks.
I will be poking around, I do believe it may be "stuck" someway in O.D.
Feels like I'm accelerating from 2nd gear.

 

bobg, I have a setup like you describe.
Make sure your cable is pulling the lever on the tailhousing all the way forward.
Make sure you know if you are providing power to the solenoid. Set it up so there is no power to the solenoid (can disconnect for a test)
With no power to the solenoid and when the cable is pulled out (and the lever on the tailhousing moves all the way forward) things are locked together and the OD ratio is 1:1 and direct drive.

You may have to roll forward gently in 1st gear to get the lever on the tailhousing to move all the way forward.

JP

 

With the tranny control lever all the way forward, the Tee Handle will be in the "out" position, going towards the seat, meaning the overdrive is disengaged. Is this correct ?
Looking at this link, is #4 control lever engaged or disengaged ?? Thanks J.P.
http://chevy.oldcarmanualproject.com/shop/1955/55csm0715.html

 

That pic is helpful. The lever in that position is in Freewheel position. If the cable is pulled and the lever moves towards the front of the vehicle it would move to locked Direct Drive position. I mis-spoke in my earlier post. Even if the solenoid IS DISENGAGED, you will have 1:1 drive when moving forward no matter where the lever is (see my attempt at a description below).

Here's my attempt at describing the OD operation

The mainshaft from the trans is connected to a sun gear
There is a carrier holding planetary gears that are spun by the sun gear.
There is an outer ring gear (with internal teeth) that is driven by the planetary gears and is connected to the tailshaft.
The carrier with planetary gears can be fixed in place forcing the planet gears to spin, or it can rotate. If it rotates at the same speed as the mainshaft it is 1:1 or direct drive. The lever forward is what locks the carrier to move with the mainshaft (essentially locks the carrier and the ring gear as one unit).
The lever back allows the carrier to move freely (freewheel mode)
There are pawls inside that don't allow the carrier to move in one direction. In freewheel mode and solenoid disengaged, acceleration will engage the pawls, lock the carrier and the ring and the system will still be 1:1, but when you lift off the gas and engine speed drops below driveshaft speed the carrier will move freely (at whatever speed necessary to make up the difference between mainshaft and driveshaft rpm). You can coast w/o putting the clutch in.
When freewheeling and the solenoid is engaged (OD on) a plunger locks the carrier that has planet gears mounted on it so it doesn't move. The mainshaft then spins the planet gears, they spin the outer ring gear connected to the tailshaft. Because the ring gear is bigger than the mainshaft it multiplies the output rpm enabling overdrive.
The shift to OD occurs when:
lever is to the back of the housing,
speed is above governor threshold
solenoid is engaged
driver lifts off the throttle allowing the carrier to start to freewheel
the solenoid plunger drops in its detent, locking the carrier and engaging OD (the carrier need to be freewheeling when the solenoid is engaged for the plunger to drop)

Some thoughts to diagnose, and a change from what I recommended before.

With the lever on the trans towards the back (freewheel mode) put it in 1st and move the vehicle forward, build up some rpms, let off the gas without touching the clutch. Does the vehicle coast (freewheel)? If so good, you have 1:1 in the tailhousing. Does it engine brake? then the solenoid is engaged or stuck. Evaluate if the solenoid has power (you can remove all power to it and tape them off for safety)

miker98 above had a point that the solenoid could be stuck in engaged position which would be locking it in OD. This potentially could happen even without power. So my earlier post about removing all power from the solenoid won't guarantee that the OD is disengaged.

Somewhere on the web is the borg warner service manual for this that has a great description of the operation. I can't seem to find it.

Hope this helps.

JP

 

When in 3rd gear, non overdrive, the ratio would be 1:1, correct ?
In 3rd gear, overdrive engaged, the ratio would be 0.7:1, correct ?
I will do my best to digest all your info.
Thank you for taking the time with me and my O.D. concerns.

 

Ah, thanks for clarifying. I was only referring to what is going on in the tailhousing. 1:1 in the tailhousing when the tailhousing is direct drive. .7:1 in OD.

 

Thanks.

 

I also set my old chevy pickup with a chevy 3 speed overdrive with a pull cable and a toggle switch. I loved it! Here's a tip............don't use 1st gear overdrive...wait 'till you get into 2nd gear to use it or the torque multiplication in first gear will tear up the sprag unit in the overdrive...ask how I know.

 

JP, that's a great explaination, better than I could do. I was doing a little bench racing with my old buddy today, and I asked what he remembered. I want to clarify a point.

The solenoid could be stuck in the "engaged" position- which we remember as being under power and extended. But in replacing the solenoid, if the pawl moves easily, getting the slot lined up and then turning the solenoid to "lock" it into place can be difficult.

I took to running a jumper wire to the hold in coil, then jumping to the pull in coil. The plunger would move out. Then, unless you got the shaft into the slot, the unit wouldn't bolt down. When you removed the jumper, the solenoid would pull up against the mounting flange, and not come out without rotating it. It was properly installed. Bolt it down, and away you go.

Maybe you could explain this better than I have, assuming you agree.

But you get that unit working, and maybe go to a little lower rear end ratio, and that 6 will drive like a V8. 2nd over is a great ratio (at least in the ford transmissions). The freewheeling also shifts easier, and is a lot easier to double clutch to low if its not synchronized in 1st. Which my T-85's weren't.

 

Good info Rocky & Miker 98038. Thanks.

 

I have discovered two issues, one a maybe, the other a certain issue.
While wife was pulling the Tee Handle OUT, to disengage the overdrive, I saw the control lever move forward, but also saw the cable and housing buckle or move, without moving the control lever its full travel.
I added another cable clamp to further anchor the cable, now the lever moves ALL the way forward, moving its full distance of travel.
I initially said the toggle controlled the solenoid, so took a test light under the car, but found the current to the solenoid remained on, no matter if the toggle was "on or off". A defective switch.
I will get another toggle switch tomorrow.
I'm hoping these two items will get this O.D. to work correctly.
All the info has been helpful. Thanks.
As said, my O.D. knowledge has been ZERO, your comments have helped.

 

You want a fairly heavy-duty switch (I'd say 20A rating at a minimum) to handle the inrush current of the solenoid. Keep in mind that if the governor isn't connected, the OD really won't be working 'correctly'....