Construction and working principles of SLIDING MESH TYPE OF GEARBOX

1. It is the simplest and oldest type of gear box.
2. The clutch gear is rigidly fixed to the clutch shaft.
3. The clutch gear always remains connected to the drive gear of countershaft.
4. The other lay shaft gears are also rigidly fixed with it.
5. Two gears are mounted on the main shaft and can be sliding by shifter yoke when shifter is operated.
6. One gear is second speed gear and the other is the first and reverse speed gears. All gears used are spur gears.
7. A reverse idler gear is mounted on another shaft and always remains connected to reverse gear of counter shaft.

FIRST GEAR:
By operating gearshift lever, the larger gear on main shaft is made to slide and mesh with first gear of countershaft. The main shaft turns in the same direction as clutch shaft in the ratio of 3:1.

SECOND GEAR:
By operating gear shift lever, the smaller gear on the main shaft is made to slide and mesh with second gear of counter shaft. A gear reduction of approximately 2:1 is obtained.

TOP GEAR:
By operating gearshift lever, the combined second speed gear and top speed gear is forced axially against clutch shaft gear. External teeth on clutch gear mesh with internal teeth on top gear and the gear ratio is 1:1.

REVERSE GEAR:
By operating gearshift lever, the larger gear of main shaft is meshed with reverse idler gear. The reverse idler gear is always on the mesh with counter shaft reverse gear. Interposing the idler gear, between reverse and main shaft gear, the main shaft turns in a direction opposite to clutch shaft.w




NEUTRAL GEAR:
When engine is running and the clutch is engaged, clutch shaft gear drives the drive gear of the lay shaft and thus lay shaft also rotates. But the main shaft remains stationary as no gears in main shaft are engaged with lay shaft gears.