Primary details (A) and intermediate (B) shafts 4-speed gearbox
1 - spring ring; 2 - compensation washer; 3 - ball bearing; 4 - spring ring; 5 - gasket; 6 - oil deflector; 7 - input shaft; 8 - needle bearing; 48 - slotted nut (or hex); 49 - compensation washer; 50 - deep groove ball bearing; 51 - spacer washer of the intermediate shaft; 52 - helical gear of constant engagement; 53 - helical gear of the intermediate shaft (for 3rd gear); 54 - intermediate shaft; 55 - parallel key; 57 - deep groove ball bearing; 58 - reverse gear of the intermediate shaft; 62 - slotted nut (or hex)
1. Remove the bearing from the input shaft and inspect it, replace it if necessary. Install the parts on the shaft in the reverse order of removal. tighten the nut (if it is provided by the design).
2. Remove the tapered bearing (if provided) from the front end of the intermediate shaft.
3. Attach the intermediate shaft to the 3rd gear (the largest gear should be on top). Pull the shaft downwards and remove the parallel key.
4. Wash all parts in solvent (kerosene) and dry. Inspect and replace worn parts with new ones.
5. Reassemble in reverse order, making sure the gear collars are facing each other.