The Ford Barn

darrell · 12-21-2020, 06:23 PM

anyone on here know anything about these transmissions.the car sit for 20 years no gears of any kind.fluid is clean.dont know if it worked when laid up.have several motor manuals but dont see anything on trouble shooting.

55blacktie · 12-21-2020, 10:45 PM

Very little Fordomatic information, as you know, is in the reproduction 1955 Ford Car Shop Manual. However, you can purchase a reproduction 1955 Fordomatic Shop Manual from early Ford/Thunderbird parts vendors. Concours Parts & Accessories has it. The part number is L5-A, price $18.70, and Concours has a 10%/minimum $10 shipping charge. I can tell you that 55 and early 56 Fordomatic transmissions are air-cooled/w no lines attached to the radiator. Although All 55-57 Fordomatics start out in 2nd gear, they do have 3 forward speeds, not 2. You have to manually shift into and out of low/1st gear.

rotorwrench · 12-22-2020, 01:44 PM

The Ford-O-Matics are unlike most modern transmissions in that they have no vacuum modulation. It's all manual off of the throttle linkage. I'd use Type F auto trans fluid if it were mine.

If there is no shift happening, the first suspect is no pressure from the pump. There is a port on the linkage side of the transmission where a gauge can be connected to do a pressure test. If it pressures up and still won't shift then it could be internal leakage or even a problem with the torque converter.

With that many years of setting, it will likely need the pan pulled anyway to check the screen if nothing else. If the pump can't pick up the fluid then it can't build pressure. Keep in mind that rubber seals and O-rings don't last forever.

dmsfrr · 12-22-2020, 02:39 PM

When I had the air cooled Fordomatic for my '55 rebuilt the transmission shop said to use Mercon/Dexron fluid. It's the usual replacement for the original but no longer available Type A.
Type F is a bit newer and can offer slightly firmer shifts but isn't compatible with the Mercon/Dexron.
Since you don't know what's in there, a full drain including the torque converter may be one of the first things to do.
If I remember correctly the torque converter can be disassembled and there are parts inside that may need replacement???
.

55blacktie · 12-22-2020, 08:35 PM

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Correct. The air-cooled torque converters are bolted together. The seal is a source of leaks. If it is removed and disassembled, you might even find an ol' timer, who knows how to tweak it to increase the stall speed, if you want to ever install a bigger cam. Liquid-cooled converters are welded, but even they can be cut open and re-welded.

12-21-2020, 06:23 PM	#1
darrell Senior Member Join Date: Dec 2010 Location: p.e.i. Posts: 1,060	55 automatic anyone on here know anything about these transmissions.the car sit for 20 years no gears of any kind.fluid is clean.dont know if it worked when laid up.have several motor manuals but dont see anything on trouble shooting.

12-21-2020, 10:45 PM	#2
55blacktie Senior Member Join Date: Aug 2020 Posts: 442	Re: 55 automatic Very little Fordomatic information, as you know, is in the reproduction 1955 Ford Car Shop Manual. However, you can purchase a reproduction 1955 Fordomatic Shop Manual from early Ford/Thunderbird parts vendors. Concours Parts & Accessories has it. The part number is L5-A, price $18.70, and Concours has a 10%/minimum $10 shipping charge. I can tell you that 55 and early 56 Fordomatic transmissions are air-cooled/w no lines attached to the radiator. Although All 55-57 Fordomatics start out in 2nd gear, they do have 3 forward speeds, not 2. You have to manually shift into and out of low/1st gear.

12-22-2020, 01:44 PM	#3
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,440	Re: 55 automatic The Ford-O-Matics are unlike most modern transmissions in that they have no vacuum modulation. It's all manual off of the throttle linkage. I'd use Type F auto trans fluid if it were mine. If there is no shift happening, the first suspect is no pressure from the pump. There is a port on the linkage side of the transmission where a gauge can be connected to do a pressure test. If it pressures up and still won't shift then it could be internal leakage or even a problem with the torque converter. With that many years of setting, it will likely need the pan pulled anyway to check the screen if nothing else. If the pump can't pick up the fluid then it can't build pressure. Keep in mind that rubber seals and O-rings don't last forever.

12-22-2020, 02:39 PM	#4
dmsfrr Senior Member Join Date: Aug 2012 Location: Abq, NM Posts: 3,607	Re: 55 automatic When I had the air cooled Fordomatic for my '55 rebuilt the transmission shop said to use Mercon/Dexron fluid. It's the usual replacement for the original but no longer available Type A. Type F is a bit newer and can offer slightly firmer shifts but isn't compatible with the Mercon/Dexron. Since you don't know what's in there, a full drain including the torque converter may be one of the first things to do. If I remember correctly the torque converter can be disassembled and there are parts inside that may need replacement??? . Last edited by dmsfrr; 12-22-2020 at 04:36 PM.

12-22-2020, 08:35 PM	#5
55blacktie Senior Member Join Date: Aug 2020 Posts: 442	Re: 55 automatic Sponsored Links (Register now to hide all advertisements) Correct. The air-cooled torque converters are bolted together. The seal is a source of leaks. If it is removed and disassembled, you might even find an ol' timer, who knows how to tweak it to increase the stall speed, if you want to ever install a bigger cam. Liquid-cooled converters are welded, but even they can be cut open and re-welded.