Originally Posted by JAG Racing
48 = rear diff gears & 19 = main rear shaft --- and then you 'll need the mid-shaft gear count and the front diff gear count if you want "over-drive" gearing ratios.
.. so it looks like the MTX-3 has an internal gear ratio of 2.53 ( or 0.396 ) depending how you define ratio - (mainshaft RPM/rear axle RPM)or (rear axle RPM/main shaft RPM)
rear diff : 49
main shaft drive to rear: 18
main shaft drive to front: 19
mid shaft driven: 24
mid shaft drive to oneway: 16
This is quite messy... I keep only with the basic spur/pinion x 2.53...
and each 2~3mm in tyres equals one spur tooth...