Lower unit 1984 200hp Merc trouble

[ChocolateBayouGator]

I am back again...I have a 1984 200Hp Merc and I am having problems with the lower unit. It engages the prop when put into gear but the propeller does not turn either forward or reverse. The linkage looks good and with the engine not running, I feel the propeller engaged when in gear, it only turns one way when in gear. What would cause this?

 

[galamb]

Back up a sec - you are checking this without it running correct?

Normally, in neutral the prop will turn freely (by hand) in either direction.

In forward, if you turn it clockwise you may hear a clicking sound, but it will turn. If you try and turn counter-clockwise it will stop dead.

Vice versa if you put it in reverse.

Is that what you are seeing? If so, it's working exactly as it should...

 

[ChocolateBayouGator]

It does exactly what you said when it is not running, but when it is running, the prop will not spin when put into gear either forward or reverse.

 

[galamb]

It sounds like one of two things - either there is a problem where the driveshaft and crankshaft mate up (chewed splines) or the pinion bearing (that should be turning the gears in the gearcase) is toasted.

Next step might be to pull the lower unit, put it in gear and turn the driveshaft by hand - if the prop turns, the pinion is fine (that would actually be the bad news).

The alternate would be either a worn driveshaft (bad and expensive) or a worn crankshaft end (very bad and very, very expensive)....

 

[ChocolateBayouGator]

Thank you Galamb for responding again. Waiting on my manual to start tearing everything apart.

 

[ChocolateBayouGator]

Okay...I took off the lower unit, put it in gear and turned the driveshaft by hand and the prop did not turn. Tried this in both forward and reverse gears. The prop would engage in both gears, but would not turn by turning driveshaft by hand. Driveshaft would turn, but sounded like rubber was grinding on rubber...not a metal sound...did have metal flakes in lower unit oil when drained. It this is a pinion gear issue, is it advised or can a novice fix this with a manual, or should it be taken to a professional to have done? Its only money...

 

[fastjeff]

I'll bet the drive shaft is sheared off where it enters the pinion gear. I've seen this before. The LU will have to come apart. Sorry.

Jeff