Splined seal, 1978 Mercury 700 70 hp

[adriancooke]

I am trying to determine where on the drive shaft the splined seal goes, it fell off of the shaft when I was pulling the lower unit, does it go all the way down to the bottom of the splines on the drive shaft? the part number for it is 86304. Any info would be appreciated greatly as this is the last thing I need to figure out before I can start putting things back together, thanks.

 

[emckelvy]

Re: Splined seal, 1978 Mercury 700 70 hp

The plastic splined piece slides down over the end of the driveshaft and sits at the bottom of the splines. From my recollection, there's only one way it'll go on, otherwise it won't slide all the way down the splines.

The splined rubber seal nestles inside the "cup" of the plastic piece, and squishes up against the bottom of the crankshaft to keep water out of the crank splines.

Here's a diagram which will show the plastic "driveshaft seat assembly" (piece #32) and the rubber "drive shaft splined seal" (piece #33):

Mercury Marine 70 HP (3 CYL.) GEAR HOUSING (DRIVE SHAFT) Parts

HTH...........ed