Parts Help Needed

jpock1976

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Aug 13, 2018
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I am also stuck on the question about model numbers and difference between A11 and M models. Cant find literature anywhere telling me. I also have 1976 omg 980709. That is all that is on the plate on the sterndrive. There is nothing on the engine giving suffix info. Also, from another thread someone said these model numbers are basically useless for finding parts. That its only an internal reference for omc. True? When i try to find parts based on my year and model and horsepower i am presented with 4 model options whuch include an M and A11 (see image) and none of the models presented match the number on the tag. There is nothing on the motor except OMC 190 and a number printed on the intake which from searching has nothing to do with the outdrive. It appears most all of the part numbers are the same no matter which model i select on this particular parts site. But there are a couple parts that require me to know A11 or M. I think maybe it means trim type? But i dont know how to know if i have manual trim or auto? IF thats what it means.

you will see 4 models here when searching by year and HP. Time to start guessing i guess. Please help.
 

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southkogs

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Welcome aboard:

You're on a good track - A11 is the fixed mount, A11M or MT is manual trim and A11ST is Select Trim. Has nothing to do with the outdrive. The outdrive might have a serial number on it, but OMC didn't do much with that. Usually people find the part number for the upper gear case more than anything else.

Your outdrive is an electric shift, and you really don't need much more detail except for two things: the gear ratios of the upper and lower gear case. I have a list of those, but it's on a USB drive that's at work (I can look for it tomorrow). And then to know your steering system - mainly if you have Tru Course. If you do, then there is a gear at the top of the upper gear case that works with your helm.

I used to look up my parts HERE and then confirm them before I ordered. Go to PARTS, and select STERN DRIVE on the drop down.
 

kenny nunez

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Just as Southkogs said about electric shift drives.
All electric shift models after 68-72 use the same seals, bearings & gaskets. After 73 the ball gears were different which is what you have, You have a low profile model. 78 and up used the 400-800 lowers which I never did care for with all the shift problems. Depending on high or low profile determines some shafts in the upper and gear ratio depending on which horse power. The lower electrics all share the same internals.
Your engine is a 302 with 351 heads and cam with the 351 firing order. If for any reason the engine needs repair be sure you stay with the 351 set up. With a 4 barrel marine carburetor you will have 225 horse power.
If you do not have hydraulic rams for engine mounts then that makes it a manual trim.
Southkogs should be able to help with the part#s that you need.
 

Redrig

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assuming nothing has been swapped over the years .

a 76 with a 190 should be .

upper 21/19
lower 15/23
overall ratio 1.39

and yeah , that link that Southkogs put . You will want to bookamrk that and use it for a reference when looking up parts
 
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jpock1976

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Hey guys, thanks a lot for all the info! I made sure to save it all. I am still a little confused about how to find out which specific model I have. Following the link from Southkogs, I get these 4 options.

nodeFolderClosed.gif
990231A11 1976
menu_tee.gif
nodeFolderClosed.gif
990231M 1976
menu_tee.gif
nodeFolderClosed.gif
990232A11 1976
menu_tee.gif
nodeFolderClosed.gif
990232M 1976

I know the part numbers are all the same anyway no matter which model I would select. And thats fine. Southkogs, you said A11 was Fixed mount and M was for manual trim. The only part in question here is Part number 47 in upper gearcase group, low profile. I am presented with the A11 vs M suffix choice. I just want to make sure I get the right one. So, based on all that was said, I need to look to see if I have hydralic rams for mounts. If so, it would be "M" If not, it would be A11. Am I correct? Thanks again. (hoping for the "M" option as A11 (fixed mount) is a ton more $$) Not sure why.
470907738DRIVESHAFT,Upper. MODELS WITH "A11" SUFFIX ONLY 175 & 190 HP MODELS
470909121DRIVESHAFT,Upper. MODELS WITH "M" SUFFIX ONLY 175 & 190 HP MODELS ONLY
 

southkogs

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Interesting - I'm finding a little conflict in my lists: 990232A11 and 990232M are showing as both being select trim in another list I have. 990231A11 and 990231M are both showing as manual trim. We might need a photo of the front of your engine to tell for sure.

If you didn't already know - the trim on an OMC Stringer happens at the engine's front. The motor and quadrant gear on the stern drive are just the tilt (never wanna' run that faster than idle/steerage speed) for shallow water or trailering.

And you're right that shaft (and another couple of parts) are different depending on the prefix. Kenny may know why off the top of his head. He's forgotten more than I've ever known about these drives. (And yeah, let's hope for the cheaper shaft, right?)

I know you said you looked on the engine for a number, but let's confirm for sure: Usually the model number is on a tag. Maybe on the engine, but more often on one of the engine mounts. Mine was on the starboard side rear mount. Your boat looks to be in pretty nice shape - I'm thinking as well cared for as that, there's a good chance the tag is there.
 

jpock1976

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Hmm. So based on the info in your list maybe the 990232 is Select Trim and the 990231's are Manual trim.. So that would mean the A11 and M do not differentiate that? Strange. Anyway, I looked again last night all over and found a couple things.. not sure if they are helpful or not. I took pictures. Attached. I dont see any hydraulic mechanism for doing trim at all.
 

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kenny nunez

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The hydraulic rams are bolted directly to the engine. The metal tubing in the picture goes to a pump mounted in the front of the engine. If the system is in good condition you will see the front of the engine move up and down.
 

Redrig

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Look towards the front of the engine , head on, not from above - in the area of alternator and those brackets . I want to say its on the bracket for the fuel filter (that is where the sticker is located on my 77)

small sticker probably 1" x 2" if I remember right
 

jpock1976

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Thanks Kenny. I will look again. Are the rams underneath way in the back maybe? After this next blizzard goes through, I will take the cover all the way off so I can get a better look.

Thanks REDRIG. I will look closer directly at the front. That help a lot!
 

southkogs

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You're looking for a tag that looks like this:
Image result for OMC 1976 stringer engine tag

This is what the hydraulic system looks like unattached:
omc-hydraulic-trim-mountsjpg.image.733x550.jpg

This one is "upside down." The cross member goes underneath the engine. In your third photo, the rams should be just inside the bracket ... hidden from view at the moment.
 

jpock1976

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I see! I will have to get a mirror or something and check again. Thanks! I will keep looking for the model #. Its gotta be there somewhere. But definitely not on the starboard side like yours was unfortunately.
 

jpock1976

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Ok. Looked again finally. Yes. My mount seems to look like the one in the picture southkogs posted. It looks like it has the hydraulic trim system. So that would indicate A11 select trim and not M for manual. Now how to know if its a 232 or 231 model? I looked again from the front of the engine and didnt see anything and nothing by the alternator either. I found some numbers on the block but they dont resemble what im looking for and are hard to make out. I may just have to throw a dart at the wall when i order the new shaft and hope for the best. Lol. Or take off the engine cover entirely to get better access.
 

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Redrig

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Sorry to send you on a wild goose chase , I now see that you have the banana manifolds and my 77 has the rear risers , so they must have put the sticker elsewhere due to that manifold change
 

jpock1976

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Thats okay. I will keep looking. Maybe it will be in the way back somewhere. Otherwise, if someone can just confirm I have the A11 vs M, I will be all set. I need it to make this decision on upper drive shaft part number. (attached photo)
 

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southkogs

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I wish I still had a shaft laying around to send you, but I've gotten rid of the few junkers I still had around. Maybe kenny nunez knows?
 

Redrig

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I know that a lot of the driveshafts have the part number engraved on them, intermediate shaft , vertical in the lower, prop shaft, etc.

Taking yours apart may be the only way to confirm
 

jpock1976

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Thanks guys. I had already taken it apart. Scanned the parts for numbers but dont see anything. Maybe i would after pulling the gear etc from the upper shaft. I did more research. I can confirm mine does have selectrim. So my model will be 990232. 990232 is selectrim. 990231 is manual. See attached pics. I still do not know what the A11 or M suffix is. But its apparently nothing to do with the trim. The M suffix part is cheaper. I think im just going to have to buy it and find out. :( frustrating. If it wasnt the difference between 170 and 400 dollars i wouldnt be so worried. Thanks all for for help.
 

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kenny nunez

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The water pump shaft #909753 0r Sierra # 18-2185
The pinion or upper shaft # 909121 or Sierra #18-2183
The seal kit #982949 or Sierra #18-2667
The lock nut #907866 or Sierra # 18-3731-9
To replace the shaft in the pinion housing takes some special tools. I still have them. If you send me the pinion housing I will rebuild the housing and mount the water pump for no charge and parts at my cost plus freight.
 

jpock1976

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Thanks for the info Kenny! & Thanks for offering to help me out. I am planning to attempt it myself. I might regret saying that. haha But I do like to tinker a bit. I'm sure I'll have more questions once I get some parts. Thanks for all the help guys!
 
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