Mercury Mariner Outboard 225 3 Litre Service Manual 1994, Page 316Get this manual
10Pull up slightly on the propeller shaft to gain access to the groove on the shaft for the keepers Assemble the two keepers into the groove and lower the propeller shaft 11 Install the second thrust collar with its STEPPED SIDE
aPropeller Shafthrust Collar
12Lubricate the second thrust bearing with Quicksilver Gear Lubricant (92-13783A24) and install it to the top of the thrust collaraPropeller Shah (slightly lifted)Keepers (2)Thrust Collar