There is a 24mm oil seal that is in the inside front cover of the starter motor where the starter shaft exits. It appears to keep any excess oil from entering the electrical components of the motor itself. Mine was damaged while rebuilding the starter, but I can not find any replacement part numbers.
The seal is a metal shell type (like the oil seal in the oil pump). Does anybody know of the replacement P/N before I pick up an old starter on ebay?