Does anyone know what the first gear ratio would be for a 1960 Fordomatic in an F100 behind a 292 Y block? Anyone have highway gears behind their Fordomatics? Another HAMBer said he thought the Fordo would be geared to high to get the truck moving. Any experience? It looks like I might be making about an 1,100 mile trip with one soon that has low geras in it now and want to weigh my options. One of the options I had was to buy another 9-inch pumpkin with highway gears (2.90ish) and just swap the highway pumpkin in there and have a quicker drive home. Thanks.
That year Furd made two Fordo's, one is three speed (but starts in 2nd and shifts to 3rd in DR, Lo is the true first) and the other is a true two speed, with LO being the same as the starting gear in DR. The true two speed I don't believe was used in F100's, but I could be wrong. In any event the true two speed is all aluminum and not cast iron as the 3 speed Fordo is (cast iron case, bell and extension housing might be aluminum). I will take it you have the the 3 speed variety. My guess you have anything from 3.20 to 3.70 gears. I would think the best cruising axle for your engine would be around the 3.20 mark. You can always use LO for starting when pulling heavy loads, then shift to DR. (Or you can floor it from start with it in DR and it will start in the first gear, a little trick) Hope this helps.
I'm pretty sure it's a 2-speed. Does anyone have any ideas? I found a website that had a bunch of info on a lot of different trannies but the 2 speed Ford-os had no gear ratio information.
I have 57 Ford truck info, which should be close, if not the same. Its giving me 1st 2.40 (supposedly 6 cyl only) 2nd 1.46 3rd 1.00 4th 2.10 (converter ratio) rev 2.00 the auto trucks had 3.70 rears or 3.89 for the v8 6 bangers had 3.89 or 4.11 This is with the auto trans.
The true two speed Fordo has around a 1:82 ratio, but is it really the true two speed you have? Here is a test: Start out in DR and accelerate at a slow rate and observe the engine RPM (tach would be great), then shift to Lo (no higher than 20MPH) and see if the RPM's go up. If they do you have the 3 speed Fordo, and not the true two speed. If they don't go up you have the true two speed. If you do have the true two speed, you may want to change out the transmission to a C4, but then you would need an adapter to do that. You could always go to the 3 speed Fordo and at least have the 2:40 LO for heavy loads. Remember, the true two speed has an ALL ALUMINUM case, front to back, the 3 speed Fordo does not. I would check this out. Another way of telling what you have is to look and see if the bell housing is removable from the trans case. The true two speed has the bell housing cast with the case.
I don't have the truck yet. I asked the seller and he said it IS the 3 speed but they start in second and shift to third, and that first is a manual granny style gear. That sounds perfect to me. I don't need an OD ****** as my plans ultimately have me putting a (gulp) SBC with 700R4 into this truck. My concern with the gears that it currently has is only for getting it the 1000 miles or so to Connecticut. I think I have my answer...the search is on for another third member. Thanks.
Any of the transmissions have the same high gear ratio: 1.00, so it really does not maztter what POS-O-Matic you have. Although you confirmed that yours is the three speed. They do start in second unless you floor it, or manually put into low. If you have tall enough tires on the back, it should being a pickup, even with 3.70 gears you can cruise the freeway. Just cruise at 65 mph instead of 75 mph. That old straight axle front end may be loose enough that you are plenty comfortable at only 65 mph. A swap to taller gear is easy enough, but you should be able to maintain reasonable freeway speed as the truck is. I had a 60 F-100 with a 292 and POS-O-Matic trans. I hated that trans. Worst part of the truck. Rest of the truck was fine, the old Y-block ran fine and had no troubles. I never had any real trouble with that trans, it just is not a good trans. Starting in second gear ****s even unloaded. It shifts bad compared to a newer automatic. A more modern auto conversion is definitely worth it. Have you figured out I am not a fan of the POS-O-Matics????
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