Questions on fluids for my 1976 OMC Stringer Electic shift sterndrive

nemo963

Cadet
Joined
Jul 7, 2011
Messages
9
I've been restoring a boat the last few years, now I'm kind of hung up and need some help.

Here is the background, my grandfather purchaced a Cobalt 18 foot bowrunner I/O new in 1976, I grew up riding the boat (he kept it in great shape) one year in the mid 80s it didn't get winterzed right and it froze the block. A couple years ago I took it off his hands with the hope of getting it back up and running. It was kept just like I remembered it, the vinyl and teak wood were all in almost perfect shape, I rebuilt the OMC (Ford 305) and it runs great.

Here is my problem, the places here in town suck at doing work on boats, I dont trust them as I have had some problems before. I want to change the fluids in the stern drive itself. I have a OMC manual and it goes over how to pull it all apart and replace major parts, but I can not find one place on how to just change the fluids.

I would like to change the upper fluid, it has a screw in dipstick right on top of the drive (flat spot) but cant see where it drains, also dont know what to use (I have heard they are picky).

I would also like to change the lower fluid as well, there is a screw in the middle you pull to look for water and level, and a lower one that looks to drain it, do I just drain it out the bottom and then squeeze new in till it comes out the top, if so what (once again heard the electric shifts are picky....there has been some mention of "type C?") and how much.

Lastly there is a little gear that raises and lowers the sterndrive, it has a screw that checks a level and nothing comes out, it says something like "only use OMC xxxx oil" but it's been painted where I cant read it and I have no idea what to put in there either.

It's a 1976 OMC electic shift stringer (I think, does that sound right). I can get some pictures if need be, just dont want to screw it up, but at the same time want to keep it properly serviced.

Thanks again for your help...also my first post here.....
 

GMC2003

Petty Officer 2nd Class
Joined
Mar 3, 2011
Messages
119
Re: Questions on fluids for my 1976 OMC Stringer Electic shift sterndrive

Welcome to Iboats. The "Little gear" is a the tilt gear, use any 4 Cycle oil in that one. The upper gearcase has a plug on the starboard side about 8 inches down, you can drain the fluid from there. I've heard of people using 80w-90 gear fluid in there but I use the OMC Type C as per my manual. Use nothing but OMC Type C in the lower unit, anything else and it will slip. Fill the lower unit from the bottom until it reaches the fill level hole, replace the (fill level) screw, and it will create a small vacuum so you can replace the drain screw. You can fill the lower unit by squeezing the bottle but I prefer a pump, it makes it a million times easier. I believe you fill the upper gearcase from the drain screw too, and fill it to the "FILL" line on your dipstick. Again, replace the fill screw, and then the drain screw. The tilt mechanism has no drain, so I just fill as needed. I can post pictures if you need.
P.S - You can get these fluids right here on Iboats.
 

oldsub86

Petty Officer 1st Class
Joined
Sep 9, 2008
Messages
311
Re: Questions on fluids for my 1976 OMC Stringer Electic shift sterndrive

An electric shift stringer should use type c oil in the lower unit, upper unit and intermediate housing so far as I am aware. I don't think it is quite as important what you use in the tilt housing. I cannot recall off the top of my head what exactly is called for but I think you could get away with several choices. I believe I recall people saying they have used 30 weight oil but you could likely use 90 weight for that matter. I think I have also read that some folks pack it with grease instead of oil.

The manual shows the drain for the upper leg on the starboard side in the middle about half way down.

Randy
 

GMC2003

Petty Officer 2nd Class
Joined
Mar 3, 2011
Messages
119
Re: Questions on fluids for my 1976 OMC Stringer Electic shift sterndrive

One more thing, I am almost 100% positive Ford never had a 305 engine. OMC had a 175HP 302 and a 190HP 302.

Tyler
 

nemo963

Cadet
Joined
Jul 7, 2011
Messages
9
Re: Questions on fluids for my 1976 OMC Stringer Electic shift sterndrive

Yup, your right, it's a 302....I'm a Chevy guy and the 5 liter "feels" like a 305 to me but it's 302 in the Ford circles (it's the 190 hp). I guess I did not see a "intermediate" housing, is there little screws I'm missing for it? Going to order the type C from here right now, thanks again for the help, gonna take it out on the water next week or so and I'm stoked!
 

GMC2003

Petty Officer 2nd Class
Joined
Mar 3, 2011
Messages
119
Re: Questions on fluids for my 1976 OMC Stringer Electic shift sterndrive

The intermediate housing screw is above the upper gearcase, right by the transom seal. This too has no drain plug, so I just fill it as required.
 

Howard Sterndrive

Rear Admiral
Joined
Nov 5, 2008
Messages
4,603
Re: Questions on fluids for my 1976 OMC Stringer Electic shift sterndrive

An electric shift stringer should use type c oil in the lower unit, upper unit and intermediate housing so far as I am aware.
that keeps it simple, and works fine
but only the lower has electricity in it, so the upper and intermediate can run 80W90 if type C not handy

I thought intermediates had a drain by 1976... early ones didn't- drain should be up underneath just starboard side of the ball gear if it has one

tilt clutch housing can use any mineral based lubricant.
 
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