Quote:
Originally Posted by Andrew Rowe
Hi Richard, see attached pics of the parts you need. You will have to take the diff out to withdraw the internal drive shaft to fit the drive gear, that has an internal spline in it, there is also a spring clip that goes on a groove on the driveshaft to hold it on, the ratio on the driven gear should be about 20 to 1 and the drive gear should be marked A5 I think ,that is fitted to the driveshaft Cheers Andrew.
|
There should be 20 TEETH on the Driven gear, and 6 on the Drive gear, giving a ratio of 20:6. By changing the tooth count of the gears, you can tweak the accuracy of the speedo. The gears are interchangeable, so you can substitute a 18 tooth or 21 tooth gear in place of the 20 to raise or lower the speedo reading for a particular driveshaft rpm.
These are standard pre-war ('35-'39) Ford (and Fordson) Truck parts. You need a 6 tooth Drive gear and 20 tooth driven gear, and they do turn up from time in a variety of sources. For example:
8 tooth Drive gear
18 tooth Driven gear
19 tooth Driven gear
20 tooth Driven gear
21 tooth Driven gear
22 tooth Driven gear