mercruiser gear-box oil


Mar 12, 2004
Just West of Edinburgh
Cruising area
Loch Lomond
Boat name
Boat make
Zodiac 550 pro open
Mariner 115 Opti
trying to find an engine coolant leak...
step 1 take off lower leg (mercruiser Alpha 1) - impeller looking weird - 3 vanes rotated clockwise, 3 anti-clockwise, so replace and reassemble ...

Do I NEED to use special marine gear-box oil, or will similar automotive stuff do the job ?
it seems to be fckin expensive ?
Forgive me if I am teaching my granny to suck eggs but when we changed the impeller of our outboard, we were advised by the service centre who sold us the parts that we should also check the plate and replace it if it had score marks. Once again, sorry if you knew that! :)

Haven't changed the oil ourselves yet so can't help on that one!

Edit: our engine is a Yammie - not sure if the impeller housing is the same on the Merc.
all info gratefully received :)

no score marks visible on the plate, so will put it back.

had no choice but to drain oil before removing the leg ... guess outboards might be different in that respect

I know nurthing
Cool. Hope you get it sorted soon. :)
three-rex said:

it seems to be fckin expensive ?

If you don't use the correct oil, you'll find the true meaning of the word "Expensive".
Marine, Quicksilver to be precise, part no 92-816026A 4, you'll need two of them, and a pump to get it into the drive, part no 91-850729A 1

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