Hi group. Im thinking about adapting an old Watson #47 gearbox to a 1956 F250. The truck has 4:56 rear differential gears which come in handy for heavy hauling, but I would like to adapt to this Watson gearbox behind the transmission to utilize the overdrive feature as the granny 4 speed and 4:56 gears wind up the motor (even in town) not to mention the abysmal gas mileage. I've got several questions I would like to throw out there before I begin to think about doing this. I haven't been able to find a manual on this #47 Watson, but from my inspection, it appears to have two underdrive ratios, a "one-to-one", and then an Overdrive ratio. Anyone have the spreadsheet on this unit? First question is, can this transmission, if desired, be installed backwards so that the two underdrive settings could be used for Overdrive instead? (just curious). Second question is regarding to mounting the gearbox behind the existing transmission. Currently I have a two-piece drive shaft setup that has a short stub shaft that comes off of the transmission going to a drive shaft bearing and then to a longer drive shaft, then to the Third member. Can this gearbox be mounted where that exhisting short driveshaft is, remove the drive shaft bearing and just have a drive shaft going straight to the third member from the Watson gearbox output? FInally, what kind of interface would I use between the output of the existing 4 speed transmission and the input to the gearbox? Thanks, John
If you're thinking of buying, look inside first. Any parts other than bearings haven't been available since the 1950s. If you do end up buying it, use it as intended, not backwards. They use mineral oil for gear lube, not petroleum base. Old timers I talked to 50 years ago never had anything good to say about the 40 series.
As for hookup, a U joint between the trans and aux is all you need as long as it's lined up correctly. Drive shaft depends on length. Under 60" for a one piece is ideal. I have an even older Watson box that is missing the yokes. Never had any luck finding any
Well, my question is apparently moot, atleast for now. I found data on my model 47 and it is one that does not offer overdrive. I will now be looking for a spicer 5831.
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