Front gear train engines use a lip style front crankshaft seal (shown) in which the rotating portion of the sealing
occurs at the contact surface between the lip of the seal and the crankshaft.
Rear gear train engines use a dual or non-lip style seal which utilize a built in wear sleeve and a concealed sealing
lip. The inner and out diameter are press-fit onto the crankshaft and the front gear cover respectively, requiring
service tool, Part Number 3164659, to remove and install.
The sealing point is internal to the seal.
Only engines with a lip style front crankshaft seal can use a wear sleeve.