Overdrive Governor

J

jackson

Member
Problem: My overdrive will not engage until 40+ mph. (30+mph in second gear).

I removed the governor. The gear shaft and gear looks fine, seems to be getting plenty of lubricant. Took the top off the governor and all looks good, except it's dry inside where the little weights are. Is this normal? No lube needed?

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Jackson, my OD also will not engage below 40 mph in third (never tried it in 2nd). It spins off the output shaft right next to the speedo gear drive and doesn't know which gear the trans is in. It should work the same in 1st, second or third.

No need for fluid where the weights are. You can check the weight operation by using a drill motor to drive the gear. My cordless Dewalt worked fine. When it is spun up the weights move outboard and the center pin moves toward the cover. If the cover was on it would close the points and complete the ground circuit. I have heard that people have adjusted the point gap but I have never tried it. Closing up the point gap seems like it would complete the ground sooner but would it be enough to drop the mph down around to 27 mph? I don't know. If you do decide to pull the points apart in the cover make sure you document the assembly with pictures / sketches / notes as I didn't and had a heck of a time getting it back together. I always verify function with a drill and an Ohm meter before reinstalling the governor.
 
Dan, thanks for the reply. The first time I removed the governor and took the top off, it had 70 years of gunk in there,,, a slightly oily mess. I used WD-40 and air pressure to clean it out, and re-installed it without any lube. Maybe I screwed something up. I don't have the guts to try and knock out that pin and get the thing completely apart. Anyway, right now, to get it to engage in town below 40mph, I shift to second gear, then at about 30mph then let off the gas, allowing it to engage the OD. then, once I shift to third, the OD stays engaged, even though I'm below 40 mph.
 
I agree it shouldn't depend on what gear you're in - very odd if that's a consistent difference you're seeing. Mine cuts in kind of low so I usually make the jump to OD in 2nd
 
The governor drives off the the final drive and should make electrical contact as soon as the speedometer is just above 25 or there abouts. Now all this means is that the overdrive electrical system is now an electrically live system and the relay has power to it for normal function of the system. The driver still has to let off the gas to allow the operating solenoid to kick in. Accelerate normally and let off the throttle and you should feel it kick in. All of the function on most governors depends on the condition and function of the flyweights and any spring action that may act on them. If the flyweights are sticky and not expanding out as they should then that would delay the breaker function to some degree.

When slowing down, the governor opens the electrical circuit around 23 mph and the overdrive drops out to standard drive. When a person pushes the throttle all the way down for passing, the ignition coil is grounded momentarily till the OD drops out to the standard gear. As soon as the operating solenoid drops out the ignition is restored to normal function. It all happens in the blink of an eye. A person can feel the car hesitate just a tiny bit before it takes off in the lower gear. As soon as the driver lets off the throttle, it shifts back into OD unless the lock out handle is pulled out.
 
Rotorwrench, As you noted, the governor drives off the final drive... so speed determines when the system is "live". The mystery deepens, because when I lift off the gas in 2nd gear, the OD engages at the proper speed... around 29 0r 30 mph (and stays engaged when I shift to third). However when I drive "normally", that is, take off in 1st, shift to 2nd, then shift to 3rd, then lift off the gas, it will not (ever) engage overdrive until I'm over 40 mph. I know it shouldn't work this way, but it does.

Perhaps the governor is working as it should, and there's something else in the OD circuit affecting 3rd gear engagement of the OD, but darn'd if I can figure out what it is.
 
When Ford & Lincoln/Mercury dealers were selling these systems they were competing with automatic transmissions from other manufacturers. They would tell the potential customer that they could pull away from a stop in 2nd gear and then shift to OD for around town driving. This made it a semi-automatic transmission in that the driver wouldn't have to manually shift gears. The clutch would only be required for starting out and stopping.

When going out on the road, I get on up to road speed before shifting into overdrive. It is ready to shift at 65 or 70 mph in the old 51 Merc. At some lower speeds, the car will lug in 3rd & over so I don't shift till it feels like it's ready. It may depend on the rear axle ratio. My old Mercs have the standard 3.91:1.
 
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Unfortunately my '50 has the 4:27:1 rear end. As long as the overdrive is working it's fine... I can cruise 65 or 70 all day. Without overdrive, at 45 mph it turns around 2500 rpm. Not sure what it would turn at 65 mph, and I don't want to find out.

Today I did every OD test in the shop manual. No joy. Grounding the governor makes the solenoid click, as it should, but it doesn't really tell you if internally the governor is working properly. Tomorrow I'm going to see if I can borrow a governor from a friend. Frustrating.
 
Using my bench grinder with a wire brush on one end.... I spun up the governor with the cover on. Using a multimeter I measured ohms from the governor lead to the cover.

The governor did appear to work properly (the points closed, completing the circuit while spinning). What I don't know is whether or not the points closed at the proper rpm. My bench grinder spins at 3450rpm. So, all I know right now is that the governor spins up and closes the points, but I have no clue if it happens anywhere near where it's supposed to.
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Assuming the governor is OK, I'm at a dead end. I have replaced all the wiring, and i have a new 12 V regulator and a new 12 V solenoid. The only other thing would be the kick-down switch, which I tested according to the Borg Warner manual troubleshooting guide,,, which said it was OK.

Jackson
 
A person would have to rig a test light to function off the governor so they could see what speed the light comes on. A tall set of gears will use a different speedometer gear to compensate for that ratio so the speeds should still be the same or at least very close. I don't know about the governor gear though. I'd have to check my parts manual.
 
Remove the governor again. Get it on your bench and remove the 3 or 4 screws holding the top cover on. The governor was made in two versions, each of which utilized a different centrifugal switching mechanism. From your photos, you have the 4 screw type. Be sure to carefully remove the very thin gasket so that it doesn’t get torn. With the cover off, clean the internal mechanism. We use our ultrasonic cleaner (hot soapy water with vibration) to clean the entire unit. You can also use a Brakleen spray can to clean it out. Use a compressed air nozzle to blow it out. Clean repeatedly until you can turn the gear and shaft easily with your fingers.

While it’s off, clean the brass contacts on the top cover. Reinstall the cover and put the governor back onto the transmission. You can test it again as you did before with the ohmmeter, but that’s not a scientific test for the actual kick in speed. You’ll have to road test the car to confirm that. There’s a fair chance that the cleaning will improve its performance.
 
I have the same warner OD in my 55 . One thing I learned about it is, if the engine is on high idle or will not idle below 900 rpm it will not drop into OD at the correct 27 mph. I thought I had a problem with the governor to but it was carburetor in the end with me not letting it warm up or pushing in the choke knob appropriately.
 
pistonbroke said:
I have the same warner OD in my 55 . One thing I learned about it is, if the engine is on high idle or will not idle below 900 rpm it will not drop into OD at the correct 27 mph. I thought I had a problem with the governor to but it was carburetor in the end with me not letting it warm up or pushing in the choke knob appropriately.
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Pistonbroke.... THAT WAS IT! I was out of options... saw you post, and reduced my idle speed. Only about 150 RPM made all the difference. That simple adjustment and my OD shifts right about 29 mph, like it should.

I double-checked my Borg Warner OD manual. No where under "troubleshooting" does it mention idle speed. I guess they figured having the proper idle speed was a given. Still not sure how my idle speed crept up to close to 1000 rpm, but you can rest assured i'll pay attention from now on.

Jackson
 
Idle speed is more fuel delivery related along with other carburetor adjustments so the overdrive maintenance instructions don't mention anything about it.
 
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