Using the 4mm Allen (hex) key remove the central screw from the handle releasing the spacer and spring.Â
Remove the turret handle. Use the 17mm spanner/wrench to remove the self-locking nutÂ
Remove the turret, large washer and thrust bearing from the shaft. Â
Clean the large washer and thrust bearing and apply petroleum jelly or lithium grease, set aside. Check that the shaft is firm on the plate.Â
If the shaft moves the cutting head will need to be removed from the cutter bar to get access to the screw in the back end of the shaft.Â
Loosen by one turn the three screws holding the two halves of the turret together using the 4mm Allen (hex) key.  Â
Reassemble the thrust bearing, large washer, turret and self-locking nut onto the shaft but do not fully tighten the nut. Move/twist the turret in all directions (except for its normal rotational movement) and simultaneously tighten the nut until any movement disappears, do not overtighten. Further small adjustments can be made later.Â
Place the turret handle back pushing the side pin through the oval hole in the turret, replace the spring, spacer and screw then tighten with the Allen (hex) key.Â
Using the turret handle check all three turret positions can be selected and locked. Tighten the three turret screws using the 4mm Allen (hex) key and test again.Â