1951 Ford overdrive

[mrlaser]

What I am concerned about whether the balk ring is not in proper position because of the synthetic Gl-4 and as a result, the remediating steps outlined in the BW overdrive manual are unable to move it into proper position due to excessive "slipperiness" (for lack of a more informed term.) The pictures were borrowed from Mac VanPelts excellent article on rebuilding an overdrive transmission. I am a complete novice on this subject and may not have a proper understanding of the function of these parts. It is my suspicion however, that the balk ring is somewhat out of position ( or perhaps incorrectly installed and as a result is preventing the pawl from completely engaging in the slot on the balk gear. As I have previously mentioned, the transmission functions normally with the OD handle pulled completely to the rear and is in freewheeling with the OD handle pushed in. Are there any steps that might clarify the situation that I can take before removing the transmission? Thanks again for any suggestions.Merc-ODtrans-Part10-4.jpg

Merc-ODtrans-Part10-5.jpg

[tubman]

Just keep this in mind : You will love it when you finally get it to work.

I am watching this closely, as this is my task (installing an overdrive) for this summer.

[rotorwrench]

I am wondering where those photos came from? Oh I see now (Mac VP). I never take the balk ring off of the gear plate. It loosens the fit and it doesn't have enough tension between the two parts. The tension is what allows the balk ring to rotate with the gear. If it's loose on there it will just stay pointing down due to its own weight.

The tension is set up at manufacture of these two parts. Once it's set, they should not be taken apart. I use a spring scale to check the tension before I can call the assembly serviceable.

The type of oil shouldn't have an effect. I use Aeroshell 100 mineral oil in my Mercury transmissions. This is an SAE 50 grade 100 aircraft mineral base motor oil. SAE 50 is the same viscosity as SAE 90 gear lube since they are graded differently.

[mrlaser]

To be honest ,I don't know whether the balk ring was removed from the balk gear during the restoration of the transmission. As I mentioned previously, the re builder has passed away. I do know that he was a very competent,long time re builder of early Fords. It has been my (uninformed) suspicion that the bulk ring is out of proper position, thus not allowing full travel of the solenoid plunger and complete engagement of the pawl in the balk gear. I thought that it might have been due to the initial use of the synthetic Gl-4 lubricant or to improper balk ring installation. After reading the tech post on The Fifth Avenue Garage Website, I was concerned that the excessive "slipperiness" of the synthetic lubricant might have prevented the balk ring returning to its proper position when the remedy suggested in the Borg Warner overdrive manual was tried. I see now that the ring itself may not have sufficient friction to allow it to be rotated in to its correct position. It has been my concern all along that the plunger on the solenoid was not fully extending. This being caused by the pawl striking the balk ring in an incorrect spot and preventing the pawl from properly engaging in the balk gear. I noticed that the "click" or "clunk" was much less intense with the installed solenoid than when it was tested on the bench. There was another suggested test in the manual which involved removing the solenoid cover and measuring the plunger for normal extension. I have not done that because I don't know how the internal wires are connected to the cover. I think that this procedure would answer the current issue. If anyone has removed one of these covers, I would appreciate some insight. Thanks Rotorwrench and everyone else for the suggestions and advice advice.

[rotorwrench]

You may be right about an engagement problem and the possible balk ring problem. I've never used the synthetic lube in a manual automotive transmission. It tends to be pricey too but I don't worry about that much. All the synthetics I use in the helicopters are low viscosity. Low viscosity lube may not be appropriate for these designs due to the need to slow the cluster down for 1st gear downshift. If they increase the viscosity then they are adding something in to do that. We use ester base synthetics for the turbine engines and for the transmissions on the helicopters. For years we just used the same lubricant but about 15 to 20 years ago they changed that. The gear lube synthesics had more EP additives than the engine oil so it added life to the overhaul period. For the old cars, trucks and tractors, I prefer the mineral based lubricants. An overdrive doesn't need a lot of viscosity so SAE 90 is fine for most uses. An SAE 85W/90 GL4 would be a decent all weather lube for them. The Stay-Lube is likely the easiest one to get. I've been using the aircraft engine oil in my old Fords and motorcycles for a long time with no problems. HD always recommended using the SAE 50 engine oil in the engine and the transmission for many years but the newer ones are all using synthetics now.

If you want to remove the cap from one of the solenoids, it's shouldn't be difficult at all. The ones with blue & orange wires protruding from the cap are self explanatory. The ones with screw terminals are also not too bad. The screws actually screw into threaded terminals under the cap. They just have an insulated carry through grommet for each screw. Just pull the nuts & washers for the cap and terminal screws then tap the cap with a wood block or equivalent and the cap should pull right off. The #4 terminal is the power up terminal. The case is ground.

[Frank Miller]

Sponsored Links (Register now to hide all advertisements)

I assume you are installing the solenoid correctly, making sure the plunger is fully engaged with the pawl. If the solenoid comes out without twisting it you've done it wrong.
Now to figure out if the transmission needs to come apart. Can you move the pawl by sticking a small rod inside the hole where the solenoid goes? It should move a half inch or so and you should feel engagement.
There was a thread some months back where the reverse lockout rod was bent. This rod moves when shifting into reverse and keeps the pawl out of overdrive. When shifted out of reverse a flat spot on the rod lets the pawl move.
You appear to have done everything electrical and I think you may end up pulling this apart. The upside is you'll be an expert on how your overdrive workss.

[mrlaser]

Frank, I did follow the instructions for the solenoid installation. It is not possible to remove the solenoid without rotating it to align the flat area first. I did wonder about a way of measuring the excursion of the pawl. Thank you for the suggestion.

[rotorwrench]

When the balk ring is in proper position, the pawl just comes in contact with the step on the balk ring. It will only go all the way in if the car is coasting. When the cart coasts after letting off the throttle, the planetary sun gear rotates backwards. This is what aligns the balk ring slot with the pawl and allows the pawl to go all the way into a notch on the gear plate.

When working on the transmission from underneath the car, it's not easy to replicate the normal function of the unit. Pulling the transmission is a PITA but it's about the only way to get the transmission on a bench to work on them. A person just needs some good snap ring pliers to aid in disassembly. I used my 1949 through 1951 Lincoln Mercury Overhaul Manual for instructions. The Mercury used an R10 type overdrive with a transmission unit that was similar to the earlier Ford side shift units and the Lincoln used the T85 with the R11 overdrive so both of these are covered by that manual. The Ford unit has no half bell like the Mercury but it is still the same in operation as all Borg Warner electric overdrives.

[mrlaser]

Once again, thank you Rotorwrench for your insights. The Ford "Green Bible" manual does not cover the overdrive or its disassembly. I have ordered the Lincoln mercury manual that you sited. I assume that the Mercury had an open drive shaft by that point. For others who might be interested, there is a well done YouTube video on GearBox Videos showing the disassembly of a R-10 OD unit connected to a Nash Healey transmission. Although the R-10 is the same as in other applications this particular car had a closed driveshaft making some of the rear portion of the disassembly a bit different.

As far as allowing time for the pawl to fully engage, when driving at 25-30 mph I turn on the (temporarily installed to bypass any other electrical issues) toggle switch, then after releasing the accelerator completely for 5-10 sec the OD still does not engage. This is in spite of hearing a slight click from the solenoid. From this I am assuming that the pawl is not fully seating in the balk gear. I realize that the transmission will need to be removed, but since it otherwise functions normally I am hoping that I will only need to address the OD itself. Thanks again.

[rotorwrench]

Lincoln is the only one that had the Borg Warner OD with a torque tube since they started using in around 1940 or so. These transmission are very long and have a real big awkward rear mount set up. All the FoMoCo cars for 1949 & up were open drive. Ford cars prior to 1949 (banjo rear)had the Columbia rear axle as an option.

You shouldn't have to worry about gear section other than making sure the reverse lock out mechanism is good & functional. Just pull the tail end parts off and inspect everything with emphasis on the shift rail, sun gear movement, and of course the balk ring & gear plate with pawl. Some have a pin that fits in the housing to lock the pawl when the shift rail is in lock out. That pin also has to function properly. It depends on the design of the lock out mechanism as to whether it has the pin or not.

[mrlaser]

Thank you for your help. I am anxiously awaiting the shop manual before diving in to this next project.

[Frank Miller]

The Ford Green bible, which I assume is the 49-51 repair manual certainly does cover it. I used it to rebuild mine.

[rotorwrench]

The Ford Chassis Parts Catalog from 1928 thru 1948 is the one I've always found referred to as the green bible but there are likely a shop manual with a similar color. Any one of them for the early to mid 50s should have the info. In 1951, the gears changed over to the diamond cut pattern but the OD was the same basic unit. The Mercury changed somewhere around February of 1951 to the same basic unit as used by Ford except it had a different bell housing & clutch. The ones used in 1952 & 53 were essentially the same for both Ford and Mercury.

[mrlaser]

I may be in error as to what is referred to as the "Green Bible" but the manual that I have in fact does not have a section on the overdrive. There may be other editions. I had to edit the pictures for size.

[zoegrant]

I had a similar situation with the overdrive in my 55. After a week of testing all the electrical parts of the overdrive system and finding that all were good I thought I would try a suggestion put forth from the B/W instruction manual.
in my case I felt that the solenoid plunger would not engage fully in the sun gear blocker ring/gear.
The instructions are fairly long for me to type out. So I will try to post here. hopefully it will work.

[zoegrant]

Attachment 433022

[zoegrant]

image.jpg

[zoegrant]

post 57 is the first part then go to post 58

[mrlaser]

As I mentioned in a previous post ( 6/1/20) I did in fact follow those steps, but unfortunately it didn't rectify the problem. I am reluctantly beginning to realize that the transmission will need to be removed. I suspect that either the synthetic lubrication has caused the balk ring to slip out of position by causing a reduction of the necessary friction with the balk gear or that the ring and/or the pawl are incorrectly oriented. Thanks again for your help.

[rotorwrench]

It wasn't uncommon for FoMoCo to print separate manuals for stuff like the Borg Warner overdrive and the Ford-O-Matic. These were used to supplement shop manuals. I have the 1951 thru 1953 Merc-O-Matic supplement but not an overdrive supplement. Some supplements are available in reprint but I prefer the originals for the photo quality.