1955 overdrive ****** question
- Thread starter zoegrant
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zoegrant
Well-known member
My fairlane is a standard shift from the factory so the gear ratio is stated to be 3.78:1...........if I install an overdrive ****** then I am thinking that if the overdrive is used only for interstate traveling I should have enough power to roll along comfortably. Am I correct ? John in CT
Ole Don
Well-known member
A stock 272 two barrel with an overdrive will keep up with modern day traffic, both in the city and on the Interstate. Don't follow close, the stock brakes fade at modern speeds.
When you walk up to the car to drive, put your mind back forty years to when the car was newer. That makes for enjoyable trips.
When you walk up to the car to drive, put your mind back forty years to when the car was newer. That makes for enjoyable trips.
40cpe
Well-known member
I think you are correct and OK with the 3.78. I had a '57 with OD/3.89 rear and stock size tires. No problems at any speed with the setup. I also converted a stock '50 Ford with the standard 3.78 rear to overdrive and there was no problem with it, either.
I installed a three-way switch in the governor wire on each of them. This allows you to drop out of OD at any time or lock it in at any time. It makes the OD much more versatile.
zoegrant
Well-known member
Tell me about the 3 way switch. ...I realize that one can drop out of overdrive by accelerating and pulling out the cable at the same time and then you are in direct drive again but it sure would be nice to not have to come to a complete stop before re-engaging the overdrive...what kind of switch and how is the hookup made ? Thanks in advance...John in CT
Frankenstein57
Member
Some cars had a kick down switch under the gas pedal, that was sort of a passing gear. My 58 has a 3.89 gear, I don't even use the cable. I have a switch on the dash, after the engine is warm I switch it on and leave it on for all gears.Then if I want to accelerate fast I switch it off. Sometimes in traffic, stop & go I switch it off. Mark
stonewalker
Junior Member
The best write-up I have seen for the BW overdrive is:
http://www.fordification.com/tech/overdrive.htm .
I know it is for trucks but it all holds true.
The Borg Warner overdrive is more than just an additional 4th gear at top end. It is a functional 5 speed. Ford used the term “Touchomatic” and Mercury will sometimes list it in the shop manuals as a “3 Speed with Semi-automatic”. Rearends were usually close for 3 speeds and 3 speeds with overdive. There were lots of variations but using a 1954 Mercury as an example you would get a 4.09 rear end with the Overdrive or you could order a regular 3 speed rear end (3.91) as an option. You would merely have to adjust the number of teeth in the speedo gear.
With the overdrive you can drive around town by just leaving it in 2nd and it slips in and out of overdrive depending on speed or use of the kickdown switch. On the highway you let it go into 4th (3rd with OD). If you want power you mash the gas pedal down and you kick down (kinda feels like and automatic with a slight pause).
When it comes to what fits, if you look in the Hollanders manual (the bible of interchange) you will find that it lists that Fords and Mercurys from 1949 to 1964 have lots of interchangeability. This surprised me at first (I was interchanging several Ford/Mercury transmissions from ’52-’54.cars at the time). What Hollanders means is that at lot of the overdrive transmissions for that period of time are all basically the same but the length or how they bolt up or how robust the inside components are or the number of splines, etc may be different. I think you will have the best luck with 1952-1956 but some of the later transmissions are more beefed up internally (starting in the 1954 Mercury) so as to handle the increased horsepower. The tail will probably read R10F-1 or R10F-1B. I did have an R10F-1A once and it looked to be match to an R10F-1. I am pretty sure the 1A is from a 1955 T-bird but I could never find specific documentation that indicted such. I never did use the 1A ****** because it was toast inside and had a cracked case from being dropped.
Bypassing the circuitry and forcing the overdrive in or out of overdrive with a switch has some inherent risks such as how the transmission self destructs if forced into overdrive and reverse is engaged. All depends on how it is done.
If you want to upgrade to a 3 speed with overdrive you will also need; the Bowden cable that engages overdrive and sits under the dash; the Governor that sits on the transmission; the Solenoid, also on the transmission; a kickdown switch for under the gas pedal; and the fused Relay that usually sits on the Cowl.
I did some scans for interchangeability from Hollanders but I cannot post them because they lose too much detail given the file attachment limitations of the forum. If you wish the scans just send me a private message.
I hope that is of some assistance.
http://www.fordification.com/tech/overdrive.htm .
I know it is for trucks but it all holds true.
The Borg Warner overdrive is more than just an additional 4th gear at top end. It is a functional 5 speed. Ford used the term “Touchomatic” and Mercury will sometimes list it in the shop manuals as a “3 Speed with Semi-automatic”. Rearends were usually close for 3 speeds and 3 speeds with overdive. There were lots of variations but using a 1954 Mercury as an example you would get a 4.09 rear end with the Overdrive or you could order a regular 3 speed rear end (3.91) as an option. You would merely have to adjust the number of teeth in the speedo gear.
With the overdrive you can drive around town by just leaving it in 2nd and it slips in and out of overdrive depending on speed or use of the kickdown switch. On the highway you let it go into 4th (3rd with OD). If you want power you mash the gas pedal down and you kick down (kinda feels like and automatic with a slight pause).
When it comes to what fits, if you look in the Hollanders manual (the bible of interchange) you will find that it lists that Fords and Mercurys from 1949 to 1964 have lots of interchangeability. This surprised me at first (I was interchanging several Ford/Mercury transmissions from ’52-’54.cars at the time). What Hollanders means is that at lot of the overdrive transmissions for that period of time are all basically the same but the length or how they bolt up or how robust the inside components are or the number of splines, etc may be different. I think you will have the best luck with 1952-1956 but some of the later transmissions are more beefed up internally (starting in the 1954 Mercury) so as to handle the increased horsepower. The tail will probably read R10F-1 or R10F-1B. I did have an R10F-1A once and it looked to be match to an R10F-1. I am pretty sure the 1A is from a 1955 T-bird but I could never find specific documentation that indicted such. I never did use the 1A ****** because it was toast inside and had a cracked case from being dropped.
Bypassing the circuitry and forcing the overdrive in or out of overdrive with a switch has some inherent risks such as how the transmission self destructs if forced into overdrive and reverse is engaged. All depends on how it is done.
If you want to upgrade to a 3 speed with overdrive you will also need; the Bowden cable that engages overdrive and sits under the dash; the Governor that sits on the transmission; the Solenoid, also on the transmission; a kickdown switch for under the gas pedal; and the fused Relay that usually sits on the Cowl.
I did some scans for interchangeability from Hollanders but I cannot post them because they lose too much detail given the file attachment limitations of the forum. If you wish the scans just send me a private message.
I hope that is of some assistance.
Last edited:
40cpe
Well-known member
A three-way switch simply has three positions: center position is like neutral, it doesn't pass any current. Another position connects to one side of the switch, or one circuit. The remaining position connects to another circuit.
In this application the center pole of the switch would connect to the governor terminal of the relay. When the switch is in the center position there is no ground going to the relay at any time so OD would never engage. One of the other two positions would connect to the wire coming from the governor that was previously connected to the relay. When switched to this position of the switch the overdrive would act as wired from the factory. The remaining position of the switch is connected to a ground. When switched to this position, the OD will remain engaged at any speed. This position can be used to "split-shift" the trans/OD creating the possibility of six speeds. Obviously, when driving in OD changing the switch to the center position and lifting the foot from the accelerator momentarily will allow the OD to drop out. While driving in gear without OD, simply select one of the engagement positions, momentarily release the accelerator and your are in OD.
stonewalker
Junior Member
Yes, overdrive engages at about 28 MPH: the governor controls that. Below 28 mph it does free-wheel. However, free-wheeling will allow you to easily shift between gears without the clutch if you are below 28, if you want. Also that non-synchromesh first gear is way easier to engage. Above 28 the governor allows the solenoid to engage the pawl for overdrive and you have engine braking back.
I leave the overdrive on most of the time and when parked I put it into reverse (cause first will “free-wheel”). If I am in the country side and it is hilly I will disengage the overdrive via the Bowden Cable as the gentleman previously indicated, so that the car will use the engine to brake. You could heat up those old drum brakes if you ride them too much.
(Older Overdrives from the late 40’s and back worked a little bit differently than discussed thus far.)
I leave the overdrive on most of the time and when parked I put it into reverse (cause first will “free-wheel”). If I am in the country side and it is hilly I will disengage the overdrive via the Bowden Cable as the gentleman previously indicated, so that the car will use the engine to brake. You could heat up those old drum brakes if you ride them too much.
(Older Overdrives from the late 40’s and back worked a little bit differently than discussed thus far.)
Frankenstein57
Member
So am I doing any harm free wheeling over 28 mph?, Mark
John Burne
Member
I mentioned earlier how several members of Ford Barn helped me put a T-5 transmission in my 55 truck. I remain thrilled with that upgrade. I have a 9 inch rear end and I cruise down the highway at 75 mph and there is more if I wanted it. The 292 is hardly working in 5th gear and if I feel like going through the gears a bit hot, it can do that too. I used a Mustang trans with a Chev S-10 tailstock to move the shifter forward for the bench seat. That is my only Chev part, although there is a Trans Am front sway bar and Toyota steering, but those are other stories. - John
Frankenstein57
Member
Mine freewheels over 28
parklane
Well-known member
At what speed does it stop freewheeling, and go into overdrive??
Frankenstein57
Member
It never does, I wired a switch on the dash and when it gets rolling past 28, I flick it on. Sometimes I'll cruise along without the od around 40-50 mph, let off the gas and she coasts like an automatic, apply the gas and it kicks back in, am I hurting it? Mark