Stern drive slipping

[gar2243]

I have a 1986 Mercruiser Alpha one
recently, I had hit an object on the river which damaged the prop.
I replaced the prop with an old one I had and went back out.
I had full power for about a 1/2 mile when I heard a fast winding sound
like it was slipping. I noticed the rpm's about 3200 and I now was going
10 mph.
Where do I start ? Is there a cluch unit that mayhave gone bad on the hit ?
I hear of drive pins ? doe this sound like that type of problem ?
Should I tear into the lower stern first ?

[Technical Support]

If the boat is still working properly at low speed I would suspect the prop hub or the engine coupler. Since the prop was an old one I would suspect that first. Then look at the engine coupler. Normally with the coupler, you smell burning rubber when it fails. It could have also taken out the splines. To check that you need to remove the drive and visually inspect them with a flashlight.

If it does not work at all, then I would suspect something in the drive. You can pop the top cover off and make sure the gears are okay, then seperate the halves and turn the lower driveshaft while shifting the drive to verify the lower is working properly.

Tech Support

[gar2243]

Stern Drive Slipping

Tech Support
Thank you for steering me in the right direction !!!!

You were right on the money!!

My old Prop, which looked in very good condition, was slipping inside
Put a new prop on, checked lower fluid for metal shavings and went back on the river...

Ran like a top, no vibration no slipping...

You saved me alot of shop money and down time....

Thanks again
Gary