This engine had the classic intermediate shaft bearing failure. I have not seen and actual data on the failure rate of these bearings but many sources estimate it to be about 1%. When this bearing fails there is typically a loud banging noise coming from the engine and and a large oil leak at the rear of the engine. To repair the problem the engine must be totally rebuilt. Chain rails, cam oil pumps and main oil pumps can be damaged by the debris from the engine. Damage to the crank bearings is also possible, but people seem to shut the engines down before the failed intermediate shaft bearing makes it that far. The engine can be repaired with a new factory intermediate shaft bearing or using one of LN engineering’s upgraded shafts with triple row bearings. These are different from the single or double row bearings that can be installed with the engine assembled. There are some tricks and special tools needed for these motors and they are a lot different from the old Porsche air cooled motors we have had a lot of experience with. I would say they are ultimately not more complicated than the old motors, just different.