force 120 shaft spline seal fell out? HELP.

Hi, I hope a FORCE 120 pro out can help me. I am a newbe to boating and got myself a 1991 bayliner with a 120 force. I am just getting ready to get to the water and decided to do some maint. got everything done and was advised to change the waterpump impeller as I dont know if it was ever done. Pulled the bottom end off with no issue. the long part of the 2 piece shaft come out also. I was doing fine untill a seal fell down a few seconds later. I have since found out that it is the shaft spline seal. It's a rubber collar with a steel disc attatched. I have the repair manual and have searched the net but I cannot find an explanation as to which end of this seal goes where. it can be installed steel end up or down but which way is right. HELP.
Also, in searching for an impeller I've found the price varying a lot. The part number I came up with is 18-3017. is there a really good impeller maker out there that I should go with.

Re: force 120 shaft spline seal fell out? HELP.

The steel ring goes on the shaft first with the groove facing up. The rubber collar goes into the groove with the tapered end up. This will seal against the crankshaft.
When you remove the lower unit, it is easy to wiggle it and the seal and collar get caught on the protruding edge of the gasket up there. It frequently falls off--no biggie.
Put a little anti-seize on the shaft splines before re-attaching the lower unit. The seal is there to keep water from getting into the spline area of the regular steel crank and rusting everything together. Anti-seize will help prevent rust too. Just don't get too generous with it. If you put on too much, it is possible to pre-load the shaft, causing problems later.

Re: force 120 shaft spline seal fell out? HELP.

Great explanation, I will have to take a closer look for the groove you mentioned as both the steel ring and the rubber are togeather, must be stuck, I did'nt realise that there was two seperate parts. have you any opinions on a reliable impeller make. Thank's , Bernie.

Re: force 120 shaft spline seal fell out? HELP.

Sierra and original factory part are the only two impellers I'm aware of and I wouldn't be the least bit suprised to find they were both made by the same manufacturer in the first place.

Re: force 120 shaft spline seal fell out? HELP.

Many thank's to Admiral and cadet, your advice was right on the money.