Primary shaft of the gearbox: 1 - thrust ring; 2 - 1st gear pinion; 3 - 2nd gear pinion; 4 - 4th gear pinion; 5 - rear bearing of the primary shaft; 6 - 3rd gear pinion; 7 - reverse gear pinion; 8 - inner ring of the front bearing of the primary shaft
The primary shaft is a block of drive gears, some of which are made on the shaft, and the other is pressed in with great tension. Therefore, the primary shaft is a non-separable structure and only the bearings can be replaced on it.
The inspection of the primary shaft, its gears and bearings is similar to the inspection of the secondary shaft.
Caution: When pressing in the rear bearing, apply force only to the inner bearing ring.
Replacing the primary shaft bearings
1. Place the shaft in a vice with soft metal pads and press out the rear bearing using a puller.
2. Turn the shaft over and press the inner race of the primary bearing.
3. Using a suitable mandrel, press the rear bearing onto the shaft until it stops.
4. Using a suitable mandrel, press the inner race of the front bearing onto the shaft until it stops. Do not forget to install the thrust ring first.