Good picture Henk. But in the above illustration from my WW2 RAF parts list, it clearly shows the separate spacer #113. I've seen both types on WM20's and never understood when the change took place? Ron
The above would be an easy fix but there can also be a more serious problem if the 1 inch distance piece [no. 111] between both bearings is worn much, they often are and think the reason is running with the nut not tight enough.
When the nut is than being tightened again, the crankshaft will move axially and pulled up against the small ballbearing which has a fixed position in the case and the sides of the rollers of the rollerbearing can get pushed against its ridge in the outerring and lock up the crank.
