lower unit oil 3.0 mercruiser i/o

[st6354]

I've never changed this before but I need to. The only srews I find is a vent screw on the side and a level check screw above that on the very top and it has like a dipstick on it.where is the drain plug and how do I fill this or for that matter how do I do all of it.Thanks to all who can help me.

 

[boathouse]

Re: lower unit oil 3.0 mercruiser i/o

there is a drain screw on the bottom of the outdrive on the lower left side, got to get down on your knees to see it on the lower gear case. unscrew it first then the vent screw. if it has a magnet on it examine for metal shavings also old gear lube should not be milky white this would mean water intrusion from leaking seal somewhere. drain gear oil. get some mercruiser gear lube and a pump kit you can screw on the the gear lube container and the lower screw. slowly pump gear lube until it flows steady out the vent screw eliminating air bubbles. install vent screw with new gasket, be sure old one is removed from plug or plug hole. remove pump attachment and as quickly as possible replace lower plug with new gasket. tighten both plugs with large well fitting screwdriver. this should do ya. GREASE gimbal bearing. Get an owners manual. good luck