Prop not engaging

[South Shore II]

Boat has been running fine. Was cruising the bay at maybe 10mph. Noticed something was about to fall overboard, so I pulled back on the throttle - maybe a little faster than I should have, but not like emergency stop. Went to put it back in gear and it just whined and no prop engaged. Started to overheat. Tried letting it cool down and attempting again, but same thing. Once started up, there's a high pitched whine, and engine temp goes up. Thoughts?

1985 18' Larson DC 175 Citation, Mercruiser M140 engine.

 

[Scott Danforth]

the wining would suggest the gears in the upper are toast

 

[Bt Doctur]

upper gears, engine coupler, broken shaft

 

[South Shore II]

What kind of repair does this involve (ballpark) - and might this just be an age issue?

 

[Rick Stephens]

Not an age issue. With proper maintenance a sterndrive will outlast the boat. No way to answer your question without first determining what is broken. Coupler is the connection from drive shaft to flywheel, takes pulling the motor to replace (couple hours). Upper gears are easily looked at by removing the top plate of the drive, would require either replacement of the drive or rebuild. Same for a broken shaft.

 

[nola mike]

What kind of repair does this involve (ballpark) - and might this just be an age issue?

Ballpark $1-1500 for a new drive, or $300 for a new coupler, plus labor. Drive replacement = 1hour, motor pull/coupler replacement, maybe 4-8 hours.