Jumping out of 4th gear is not unusual for the Sachs 200 engine as most shifting is done between third and fourth when on the open road. This was always a difficult problem to solve and there were cases that even the factory mechanics could not cure. However, it is not common for the other gears to jump out of their selected positions into the adjacent neutral point. If this happens, double check the oil level in the gearbox. Use the clutch inspection cover to verify the oil level - it should be level with the bottom of the clutch inspection aperture.

This work is much easier to complete while the engine is out of the car and is certainly something that should be investigated during an engine overhaul. With many of these assemblies approaching fifty years old - many different people may have dismantled and adjusted parts each with varying skill levels. Measurement of these moving parts is not covered in any of the manuals because it was rarely required. Now that the parts are so much older, we have to correct wear caused by corrosion and incorrect assembly.