Bent prop shaft

[3ric]

I just bought a new to me 2018 Merc 150 outboard 4 stroke. My heart sank this morning when I realized I overlooked a bent prop shaft in the purchase . It appears to be severely bent, about 1/16” or less off center. It shifts great, so I am thinking/hoping the damage may limited to the shaft.
Q1: is this too bent to be straightened?
Q2: what are opinions on aftermarket shafts. OEM ones appear to be about 2-3 times the cost of aftermarket, if aftermarket is a quality option, any recommendations on brands etc?
Q3: anything else I need to look for when I have the thing apart?

 

[racerone]

There may also be damage to gear teeth.----Can't be seen.-----But often results in stripped teeth at a later date.

 

[Scott Danforth]

if the gear teeth are damaged, the bearing took a hard hit too. inspect for brinelling marks.

 

[Chris1956]

Why not see what Sterndrive Engineering (SEI) has in new gearcases?
Price out the replacement prop shaft, three new gears and two bearings, and compare to the replacement cost. Without labor, I will bet it is close.

 

[3ric]

if the gear teeth are damaged, the bearing took a hard hit too. inspect for brinelling marks.

I had to google brinelling. Thanks for the new word!

 

[3ric]

All wise words. Thank you all for the advice. I’ll get her cracked open in about two weeks and see how those gears and bearing surfaces are doing and go from there. You all are great. Thanks!

 

[Chris1956]

Have you rebuilt a gearcase before?

 

[boscoe99]

Propeller shafts are bent all of the time without suffering other damage. Suspect yours is the same. Straighten the shaft or buy new. Boat on.

 

[3ric]

Have you rebuilt a gearcase before?

Yeah, just one though. It was a 1985 Suzuki dt65. Seemed pretty straight forward. Any reason to believe this one will be more complicated or difficult?

 

[Chris1956]

I have no idea of the complexity of the rebuild. However, what I have found is that if you need to replace three gears and the shaft, it will cost nearly as much as a new aftermarket gearcase.

 

[3ric]

I have no idea of the complexity of the rebuild. However, what I have found is that if you need to replace three gears and the shaft, it will cost nearly as much as a new aftermarket gearcase.

Im going to keep my fingers crossed that boscoe99 is right, and that it’s just the shaft.

 

[3ric]

I got the gearcase open. The nut and bearing carrier came out easy peasy (nothing ever goes that well for me, so now I’m nervous). All the gears look to be in good shape no visible wear or brinelling.

Q1: should I replace any of the bearings? Everything seems to spin smooth and is otherwise appearing undamaged, but I have to imagine a damaged bearings might not show visible signs?

Q2: how do I get the shift shaft out.!? I popped out the retaining ring, but the plastic bushing is not budging. Do I need to get mean with it (by making an improvised slide hammer type thing) or is there some trick?

 

[Mc Tool]

My Dad clubbed the edge of the ramp ( many times ),mangled a few ally props, bought a stainless prop and next time he bent the shaft ( prop was ok ) Being how it was christmas on the lake , no where to get it fixed so we removed the prop , lined up the shaft and smote it with a fence post . He never replaced the shaft .....because the motor was always a dog ( 1985ish Suzuki 150hp ) I fully expected something to break later on but it never did .
But dont do it ........we got lucky

 

[3ric]

Ok, never mind

My Dad clubbed the edge of the ramp ( many times ),mangled a few ally props, bought a stainless prop and next time he bent the shaft ( prop was ok ) Being how it was christmas on the lake , no where to get it fixed so we removed the prop , lined up the shaft and smote it with a fence post . He never replaced the shaft .....because the motor was always a dog ( 1985ish Suzuki 150hp ) I fully expected something to break later on but it never did .
But dont do it ........we got lucky

you story installs confidence. Thanks!

 

[3ric]

And never mind on Q2: i got impatient and ended up wrapping the shift shaft in a towel and clamped on some vice grips, then tapped (ok more than a trap) the vice grips aggressively and the bushing reluctantly came out.

 

[Mc Tool]

Ok, never mind

you story installs confidence. Thanks!

yeah and now that I have thought about it a bit more .....1/16" is F A like 1.5mm , Dads was more like 1/4" 6mm . Know anyone with a press ?