The gearbox is the second stage in the transmission system, after the clutch . It is usually bolted to the rear of the engine , with the clutch between them.
Modern cars with manual transmissions have four or five forward speeds and one reverse, as well as a neutral position.
The gear lever , operated by the driver, is connected to a series of selector rods in the top or side of the gearbox. The selector rods lie parallel with shafts carrying the gears.
The most popular design is the constant-mesh gearbox. It has three shafts: the input shaft , the layshaft and the mainshaft, which run in bearings in the gearbox casing.
There is also a shaft on which the reverse-gear idler pinion rotates.
The engine drives the input shaft, which drives the layshaft. The layshaft rotates the gears on the mainshaft, but these rotate freely until they are locked by means of the synchromesh device, which is splined to the shaft.
It is the synchromesh device which is actually operated by the driver, through a selector rod with a fork on it which moves the synchromesh to engage the gear.
gears for Diesel engines 20HP~30HP
Complete sets of automobile gears and gear drive
gears and gear shafts for automobile engine
gears for Diesel engines 15HP~20HP
Steering Gear for automobile
timing sprockets for engline