Low Geared F1

Q.

I have a 1949 Ford F1 pickup (Hope I can sneak in a Ford question). Is there a later differential with higher gear ratios to “speed” things up?

A.

Low gears are a common issue for many early truck owners as most were used as tools to move stuff and rarely seen as a vehicle for general transportation. In 1949 Ford commonly used gear ratios of 4.27:1 and 3.92:1 on F1 pickups. These are gear ratios that can make modern highway driving difficult or even impossible.

Many convert these trucks over to a more modern 9-inch rear axle that offer a wider range of gear ratios. While the 1957 to 1972 F100 9-inch axle is a close fit, it will still require some modifications, which commonly include shock mounts and sometimes pinion yoke to reconnect the driveshaft.

Another option is to locate a 3:73 higher gear rear axle for the F-1 that was offered from 1948 to 1950. These are a little harder to locate but they’re out there.

Finally you could change the gears in your rear axle. There are sources that offer 3:54.1 rear axle ratio gear sets for your truck. If you’ve never done this though I would encourage you to get the hands-on assistance of someone who is familiar with these axles and how to properly setup the gears.

Wrench Safe,
Mark

Discussion
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7 Responses to “Low Geared F1”
  1. HDMania
    HDMania

    As long as you have a welder or a torch or plasma cutter you’re good to go..measure your rear end from backing plate to backing plate..use that measurement for a new rear end..plenty of different gear ratios out there to choose from..probably get one from a newer truck..maybe one with disc brakes too..what ever you’re comfortable with..use one from a car or truck..

    Reply
  2. Paul arnold
    Paul arnold

    Have a 46 Chevy 3/4 ton 216 cu in 4 speed never use first (crazy ) that can’t get past 45 mph ?? Without the motor screaming help

    Reply
  3. gary
    gary

    8″ out of maverick, Granada would work great, 491/2″backing plate to backing plate

    Reply
    • John McGinnis
      John McGinnis

      Most Granada Rear end Gears were 2.89 to one. But a 9″ Ford can replace the Pumpkin with no problems. You will want #.4 – 3.5 Ratio for highway use.

      Reply
  4. Fred Hollen
    Fred Hollen

    Same problem with a 55/56 Dodge C-3 pickup. Any possibility of using an automobile diff?

    Reply
    • Customer Service
      Customer Service

      Hey Fred,

      Here’s what the experts had to say about your question:
      Yes, an automotive rear axle would be a good choice for your ride.
      A 8-3/4″ Mopar mid sixties to early seventies B-body rear axle should bolt right up… and the wheels should bolt on too…
      As most D-3’s had 5×4.5″ bolt circle wheels.
      If you’re not fanatical about the manufacturer, some 9″ Ford year axles will bolt up as well.
      With both options there’s a wide selection of gear ratios available.
      You may need to change out the rear yoke on your driveshaft to mate up to the new axle however.

      Mark
      Classic Car Restoration Club Expert

      Reply