Third gear:

Third gear ratio =

As, 1.333 is near to 1.38 then 1.4286, thus,

t_C   = 24            and      t_D = 36

The top gear needs direct connection among input shaft and output shaft.

For reverse gear an idler gear will be required to alter the sense of rotation. A gear is provided on the output or main shaft and a pinion is provided on counter or the lay shaft. These two must have some clearance and must not mesh each other. An idler gear is brought through the side where it rests to mesh these of two gears. This idler gear may have any number of teeth based on space available since its number of teeth will not affect the gear ratio. In order to provide adequate clearance among pinion and gear of reverse gear, assume number of teeth on pinion is 18 and number of teeth on gear is 38.

The arrangement of gears in reverse gear will be as illustrated in Figure

   Reverse Gear