Gearbox oil change

apshutt · 06 January 2015, 16:02

1970 Evinrude 6hp Fastwin. I am currently letting the oil out of the gearbox and wondered should I run some "detergent" oil around it first, before filling it again? Do you have any other methods of exchanging the oil?

Thanks Andy

Peter_C · 06 January 2015, 17:57

It doesn't hold much oil. If what came out is bad, run it for a trip, then change it again. If it is still bad, do it all over again, until it comes out clean.

uncle al · 07 January 2015, 09:01

Is the gear oil milky white? If so it could be water ingression which needs to be sorted.If its a cream colour just re-fill the gear housing, and if it hasnt been changed for a long time it will smell bloody vile, and usually drains out coloured black.Only use marine gear oil, NOT automotive gear oil .

apshutt · 07 January 2015, 09:07

Thanks to you both. No water ingress and yes got some marine gearbox grease/oil.

otilly · 07 January 2015, 11:00

uncle al, could you explain to me why not to use automotive oil?? Since I was thinking about doing this in the near future.

apshutt · 07 January 2015, 11:41

This is the oil I will be using

uncle al · 07 January 2015, 14:46

otilly the reason is, marine gear oil is formulated in such a way that it sticks to the g/h parts ,and if there is any water ingression then it is supposed to keep the water away from the g/h parts.Thats the theory anyway, Automotive oil doesnt do that.