Re: Help with a MERCURY 110, 9.8hp

[mercuryspecialist]

John,

The two most common leak points are the driveshaft and shift shaft bushing oil seals, except when fishing line is present as wisely advised. The driveshaft oil seal is in the plastic water pump housing (there is an o-ring for the water pump housing to gear housing), and this does not require special tools (do however check for grooving of the driveshaft seal area). Likewise, the aluminum shift shaft bushing does not either (also has an o-ring on outside diameter), but do use extreme caution when sliding the bushing off the shift shaft to not allow the shift shaft to rise very much, or it will come out of the shift cam below, and the gear housing would require disassembly to refit. To replace the propeller shaft oil seal can be tackled by removing and replacing if the shaft is not grooved or damaged (hard chrome plated steel surface is fairly durable), but to remove and replace the bearing carrier to then replace the oil seal would require a tool, or to make one, to unthread and retorque the gear housing cover.

Regards,
Joe