Stern Drive Oil Change

[jak2108]

Hi,
I have recently bought a mercruiser 4.3L 1990 with an alpha one sterndrive. I was told it would be a good idea to change the water pick up impeller because the boat had no history with it. So, changed the impeller today but when removing the lower drive housing lost a fair bit of stern drive oil. Not a problem because I want to give everything a complete service anyway. When Ive looked in the manual it says the stern drive oil must be filled from the bottom through the drain plug using a pump., I have noticed that there is a filler at the top and also the air vent is located on the side at the top. Why cant it be filled through the top filler and if it has to be pumped in from the bottom can someone tell me where to get the correct pump for this job or is there a DIY method which could be used.
Thanks

 

[airdvr1227]

Re: Stern Drive Oil Change

Others will chime in shortly. It's my understanding that filling from the top can allow for an air bubble and misreading of the fluid level on the dipstick. I've also heard that you should fill from the side but rather than the bottom but can't remember why.

Those types of fill pumps are widely available. Got a boat store nearby?

 

[Dave1251]

Re: Stern Drive Oil Change

Pump from the bottom to aviod air bubbles in the drive. Next time, drain thge drive before you pull the halfs apart.

Purchase the pumps at any boat supply shops. The Merc pumps only cost about$10.00

 

[Bt Doctur]

Re: Stern Drive Oil Change

Mercruisers are filled from the bottom untill it comes out the top

 

[bigskiohio]

Re: Stern Drive Oil Change

why didnt you drain the oil first?