Z50 Rebuild Guide
Taken/translated from puchforum.com
2-speed block overhaul
The reconditioning of a 2speed is more difficult than overhauling an automatic block. The block consists of more parts and is a little more difficult to put together, mainly because of the loose needle bearings. Yet you will see that it all fits together very logically. What you can replace as the reconditioning of a 2speed block, note the prices.