Exploded or cross-section illustration of GOVERNOR for Borg Warner Overdrive?

[TxCajun]

Exploded or cross-section illustration of GOVERNOR for Borg Warner Overdrive?

I need ot try to repair the GOVERNOR on a transmission that I recently bought, a late 60's Saginaw 3 speed manual with R10 Borg Warner overdrive. The GOVERNOR is a later design unit where the top is secured with rivets (rather than screws) and has the smaller thread for securing it in the overdrive case.
The rivets were loose when I got it and there is some corrosion and muck inside the GOVERNOR body. An illustration would be helpful in attempting to disassemble and repair.

[The Rocknrod]

Here is a service manual - https://www.yumpu.com/en/document/re...ebaker-infoorg

[TxCajun]

Rocknrod,

Thanks, that's a pretty detailed manual, but it doesn't address the GOVERNOR.

I'm guessing that 50 years ago the GOVERNOR was a remove-and-replace item. However, I was hoping that someone here might have some additional information that would help me try to repair mine.

Regards,

[The Rocknrod]

PDF auto download - Page 47, 48 and 49?
https://www.google.com/url?sa=i&url=...AAAAAdAAAAABAS

Is this the governor?

[TxCajun]

Rocknrod,

That's pretty interesting, but the GOVERNOR shown in that second document is a "hydraulic" governor or pressure regulator used in a Borg Warner hydraulically actuated overdrive. (I actually have one of those in a '64 Triumph TR4 that I am renovating.)

However, the overdrive used with the Saginaw 3 speed in the 50s through 70s Chevys is electrically actuated by a solenoid. In this case, the GOVERNOR provides a connection to ground for the solenoid only when a certain transmission tail-shaft speed is reached, equivalent to about 28 miles per hour. The GOVERNOR has some rotating weights that are driven out and upwards by centrifugal force, pushing a shaft that actuates a spring loaded switch to make the circuit.

Thanks for the info.

Regards,

[TxCajun]

And in the illustration that you attached, the GOVERNOR is not shown. It would be on the other side of the transmission from the speedometer drive, but is drive by the same gear as the speedometer cable.

[TxCajun]

Here are some pictures of the GOVERNOR that I want to refurbish.

Since the drive rivets that held the top on are broken, I'll try to drill and tap the body for screws.

I should be able to just clean up the switch parts and file the contacts in the cap.

What I'm not sure about is how the springs and weights in the body are supposed to work. I already cleaned out the gunk and corrosion with some electronics cleaner spray, but the weights seem to move too easily, as if the springs are broken or missing, whereas they are not supposed to actuate the switch in the top until reaching 600 to 800 rpm depending on rear axle ratio.
.

[AussieinNC]

This is all I have to offer right now...

I may have more detail after I dig deeper into my archives...

Hope this helps...

[TxCajun]

I disassembled the body today. There appear to be no springs associated with the centrifugal weight mechanism, so maybe the only springs affecting the opening and closing of the switch are in the cap.

Below are a couple pictures of the exploded parts (less the drive gear), and of the centrifugal weight mechanism in the up and down positions.

.

[AussieinNC]

In one of your pics the "petals" you see are the weights. The governor is obviously not rotating so the petals are "flat".
When the governor gets to a certain speed, they form a "cone", forcing the shaft "into" the body (towards the driven gear). Your pic of the petals lifted up shows the engaged position.
Note this internal shaft slides with respect to the external shaft so from the outside you don't see any change.

It's pretty clever: all rotating parts are mechanical; there are no rotating brushes or anything of the sort.
The dark lever in the center touches the shaft in the governor.

The switch itself is the copper "horseshoe" and the L shape riveted through the end plate in a sort of "phenolic sandwich".

The hysteresis in the overdrive switching (the fact that it switches on at 28 mph and off at 22 mph) is entirely in the design of the lever, the spring, and the horseshoe (all mechanical). Pretty clever. I believe the spring and the horseshoe are no longer available as parts.

When you actuate it, it almost feels like there's a magnet in the switch but I think that's just the layout of the bits and the action of the spring.

When the governor switch is closed (the solenoid would be on and you'd be in overdrive).

In it's natural, non-rotating position, the governor shaft would push the black lever into the recess and open the switch.

You can test the governor action using a battery operated drill and spinning the governor shaft with the governor fully assembled.
Use an Ohm meter across the electrical contact and the body of the governor...spinning the shaft should close the contact and provide a completed electrical circuit.

[TxCajun]

AussieinNC,

Thanks for the governor information! I'm waiting on a seals order to arrive then will finish cleaning and re-assembly of my unit.

You obviously know a lot about these overdrives, so I was wondering if you could help with two other questions.

1. For my transmission, the overdrive body has a 7/8 inch female thread and the governor has a 7/8 inch male thread thread where they mate. Other Borg Warner governors that I have seen have a larger thread (not sure of size, perhaps 1 1/4 inch). Do you happen to know why the difference, or is it a newer vs older model design?

2. For the Borg Warner solenoid, do you know how to remove the coil and get access to replace the shaft seal in the solenoid body (not the other shaft seal that is in the overdrive casting body) ?

[AussieinNC]

The difference in the thread size (and there are only two that I know of) is early and later series.....

On the solenoid dismantling, there are two nuts on the end of the body, undo those and the end will come off the solenoid.

The shaft seal is available by dimensions from a large bearing supply shop...it is contained in the overdrive case itself, not on the solenoid itself.

When you get ready to install the solenoid the first thing you want to do is line up the solenoid shaft so the flat spot is at the 12 o'clock position. Next apply battery power to the number (4) terminal on the solenoid. Then ground the case of the solenoid which will make the solenoid shaft extend out. Now carefully slide the solenoid shaft past the seal (a little white grease or Vaseline in the center of the seal and on the end of the solenoid shaft works wonders) until the shaft engages into the pawl in the transmission. Once it is engaged turn the solenoid to secure the pawl into the grove of the solenoid. Release the ground and the solenoid shaft should retract... and if you got the pawl into the groove at the end of the solenoid shaft correctly the solenoid itself will be pulled towards the transmission. If you always install your solenoid this way you can be 100 percent sure the solenoid is installed correctly. Line up your bolt holes and you are done.

Note....if you find you need a new solenoid, the shaft length that sticks out of the body comes in two or three different lengths...make sure the old shaft length matches the new unit.

The solenoid uses two coil systems, one to engage and one to hold in position...so make sure the solenoid is the correct voltage...you cant use a 12Volt solenoid on a 6 volt vehicle...by using a voltage divider.

If the solenoid tests ok as far as moving the shaft in and out...I would leave it alone....there are really no servicable parts inside the case.

[cwcarpenter98]

Based on the plastic cap and thread pitch of your governor, you have the 7 bolt side cover overdrive trans. The 4 bolt side cover overdrive has a governor with a metal cap. The picture in post #8 shows the metal cover. If your plastic cap is broken or cracked, you might have to end up replacing the entire governor

[TxCajun]

I cleaned up the internals of the governor, lubricated the moving parts (pivot points on the centrifugal weights and on the "trip switch"), filed the electrical contacts, and installed a replacement shaft seal. The old seal was marked C/R 07412 M1; I found 330385 listed as an interchange and purchased that.
The cap on this governor was originally held in place with some swaged pins but those had broken and allowed the cap to be loose and allowed assorted gunk to get in to the mechanism. I drilled out those pins and tapped the body for 4-40 screws to secure the cap.
The pictures also show the rubber cover that I purchased.
The last picture shows a range of actuation rpm's. I can spin the governor with my drill and it appears to be opening and closing the contacts, but I have no way of measuring the actual rpm. Once I install the transmission in the truck, I'll have to play with the screw adjustment for the switch actuation to approximate the 28mph that is recommended.

[TxCajun]

I also disassembled the solenoid, cleaned it up internally, filed the points, and lubricated the moving parts.

After some investigation and poking around, I was finally also able to remove the shaft seal for replacement. This is rather difficult because there is no access behind the seal to drive it out because the coil assembly is in the way. I fashioned a small chisel from the hardened shaft of a small screwdriver and gently tapped away at the metal housing of the seal until I could deform it sufficiently to pull it out. This seal is apparently the same shaft seal as is used to seal the shaft in the transmission tail-housing so I ordered a second one of those and installed it.

The solenoid bench tests ok now, but it will be awhile before I can test the transmission in the truck.
.

[cwcarpenter98]

You did a lot better on that seal than I did! I'll have to try it again some time.

If the solenoid is working on the bench, then it will also work in the truck as long as you have your wiring set up correctly.

My opinion is to use the wiring as GM and Borg Warner did, but others have found different ways to make it work. The only modifications I made was for the HEI distributor and adding a kill switch in the power wire between the fuse and the relay so I could completely shut the system down when driving around in lockout. Driving around college is a lot easier as a regular 3 speed than with the overdrive.

[lutronjim]

A good friend helped me wire the OD when I installed in my 70. With a regular dizzy and coil you wire to the point side of the coil to make the engine lose power. Since I had a HEI he simply wired to the tach terminal - didn't have tach. I was sure it would fry the module but it worked like a champ for several years.

I am not recommending anyone do this - but it worked in my case.

Maybe and HEI expert could explain/verify.

[lutronjim]

TxCajun

Do you have the part number for the solenoid?

Thanks

[TxCajun]

Originally Posted by lutronjim

TxCajun

Do you have the part number for the solenoid?

Thanks

The part number for the solenoid (the embossed number on the cap) is 12VAR100-62.

The seal that I used for the solenoid is the same one used in the body of the tailhousing for sealing the solenoid shaft. I purchased it from Vintage Auto Garage PN 07410S but I've also seen on this forum that an equivalent substitute is SKF 3050.

[lutronjim]

Thanks