76 Sterndrive Gearcase Fuid Change

[zag123]

So, I've been looking through my 1976 OMC owners manual for my OMC 235, trying to determine how and when to change the fluids in the upper and lower gearcases. I know how many ounces, as stated within the manual, but not sure who makes an equivelent gearcase fuild for these old electric shift units. Can anyone provide a recommendation, by brand, for gearcase fluid? Can anyone tell me where to drain and refill the upper and lower gearcases? As I have just purchased this boat, I want to change out the fluids before putting too many hours on the boat.

 

[bruceb58]

Re: 76 Sterndrive Gearcase Fuid Change

Your lower will need a type "C" lube.
http://www.iboats.com/Type-C-Gear-Oil/dm/view_id.45019
In the upper you can use non type C if you want.

 

[zag123]

Re: 76 Sterndrive Gearcase Fuid Change

Thanks for the recommendation on the fluid type. Where do I drain these gearcases from? And how? Also, how often do I need to change the fluids?

 

[bruceb58]

Re: 76 Sterndrive Gearcase Fuid Change

I haven't owned a stringer drive since 1982 so can't help you with that. I would change it every 50 hours or yearly, whichever comes first. Stringers are notorious seal leakers so I would be checking the fluid appearance constantly.