Disassembly
1. Loosen nut 92d and remove blocking plate 92e. Remove disc spring 70e and thrust washer 70d.
2. Remove steering shaft 70g, thrust ring 70b and circlip 70c. Two locking rings are installed on models with a contact spiral. Press the ball bearing out of the tube using the steering shaft and replace it.
Assembly
1. Press the ball bearing 70a into the outer tube 81b until it stops. Insert steering shaft 70g. Press in the second ball bearing 70a.
2. Install thrust ring 70b and circlip 70c together on steering shaft 70g. Make sure the retaining ring 70c is locked in position in the groove in the steering shaft.
3. Install thrust ring 70d, disc spring 70e and new stop plate 92e with the lugs towards the nut. Fit nut 92d and tighten by hand.
4. Check up ease of rotation of a steering shaft. The steering shaft must not have axial runout in the tube and must rotate without jamming.