Broken Drive Shaft

Dsawyer

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Apr 21, 2019
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OMC Electric shift, any idea why this may have happened? Looks like it got hot and eventually snapped off at around 25 kts about 5 minuets into the boat ride. I did change the freeze plugs and in the process I had to Jack the motor up but I don’t think the alignment would be off because I didn’t unbolt the intermediate housing or drive shaft. Super confused on this one. Also not sure I can’t change a shaft so might have to buy a whole new lower.
 

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southkogs

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My first guess is an issue in the lower gear case. How's the gear oil? Any metal shavings or anything like that?

If you changed the core plugs, I'm assuming this is a new to you boat?
 

froggy1150

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Nov 3, 2017
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Can't remember off the top of my head for sure but I think you have to put a wrench on the nut at the other end of that shaft then spin that end of the shaft with a splined socket tool to get shaft out. Maybe you can weld on to bearing to pull that then weld a nut on shaft.... not positive...
old timers/Alshimers
 

Redrig

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Oct 13, 2009
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Wild ! That is a weird place to snap I would think .

fixing that is going to be a pain and you do need a special tool to get it done .

Find a working lower , swap it in and be boating again the next day , I personally wouldn't bother fixing that . Lowers for those a re cheap at least where I am
 

Dsawyer

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Apr 21, 2019
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I’m leaning towards a new lower, I can’t find many out there in CA though. Saw one on eBay for $900 then of course there’s the guy in Canada who seems to do good work but he wants $1500. For some reason the shaft heated up in that spot so much that it just twisted itself apart. I have no idea what could have caused it to heat up that much. You can see how the oil looked when it came out - sorta milky.
 

southkogs

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Is this a new to you boat?

The reason I ask, is that the OMC Electric shift is obsolete. I would be hesitant to put a ton of money into fixing the system if I just wanted a reliable boat. The money (unless you can find a good inexpensive - a few hundred bucks - lower) would be better spent on buying another boat with a not so obsolete system. If you don't really know how solid this driveline is, and you pour $1k into just getting the lower fixed, you'll probably find more gremlins that will start grabbing your wallet.

If you like the boat, and want to restore it, that's a different story.
 

Redrig

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Oct 13, 2009
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the upper bearing probably siezed , the shaft snapped right above that bearing . Does the bearing spin right now freely ?
 

Dsawyer

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Apr 21, 2019
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The needle bearing spins with the shaft...not sure if it’s supposed to do that....looks wrong to me. I think the needle bearings may have rusted to the shaft and then the outer case for the needle bearings spun agains the housing until it was red hot then the force whilst the propeller was under load caused the shaft to break. Still working on a solution to get the old shaft out. Maybe wedge a screwdriver in the drive shaft on the bottom end to lock it so I can get the lock but off the bottom of the shaft. I plan on keeping the boat and am well aware of the drawbacks to the OMC setup. When I have the space and time I plan to redo the transom for the mercruiser setup.
 

Redrig

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To get that shaft out the reverse gear has to come out , then the pinion nut .

So I guess what I'm saying is that shaft ain't coming out without some more surgery
 

kenny nunez

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Jun 20, 2017
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The reverse gear also has needle bearings and the hub is probably rusted/pitted. The only parts that are salvageable are the 4 screws that hold the propeller shaft cover, the 8 swivel bearing, the 4 that hold down vertical shaft retainer, the reverse coil, the propeller shaft if the seal surface is not worn out, and maybe the swivel bearing with new seals installed.
 

froggy1150

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Nov 3, 2017
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as for the bottom of the drive where the output shaft is you will need a large set of snap ring pliers. the ones i used have handles about 18" long i think. even with those it was kinda tough. you WILL NOT be able to get the reverse coil out without this tool. this snap ring is behind the seal cap. behind the coil you will the lower pinion gear and a nut on the bottom. when i took mine out all i did was take the old matching female shaft from the upper and weld a nut on it to make the splined socket for the top. you dont have that option. your best bet would be to weld some chain to the bearing races to pull the whole bearing out. from your pick i doubt that you can get it out any other way. chain connected to a slide hammer should work. once the bearing is out i would weld something onto whats left of that shaft to be able to spin it from the top to remove the lower nut. either weld a nut from the middle or a piece of flat bar. remember if you use a nut it has to be big enough to plug weld the center but small enough to get a socket on.
 

froggy1150

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Here is the nut that must come off
 

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froggy1150

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Use a good 220 wire feed welder. Do they think a 110 will give you the penetration you need and stick would be tough and too dirty
 

Dsawyer

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Apr 21, 2019
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I used a channel lock retainer ring tool from Home Depot to remove the ring and wedged a lead sinker in the gears between the drive shaft and forward gear....this gave me just enough bite to remove the drive shaft locking nut. As you can see by the pictures the bearing on top of the drive shaft was the culprit.
 

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Dsawyer

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Apr 21, 2019
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Looking for a new shaft online...seems some of them have the o ring near the top. Anyone know theses two shafts are interchangeable?
 

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