87 Alpha on 1990 4.3. with about 800 hours-+.. This started late last season all at once as I was coming up on plane, a bit of a vibration and a small shucking sound in conjunction with the shaft turning. I didn't hit anything and it had been years since Iknocked a 2 x 8 floating. that just nicked up the prop a bit. 24 year old boat I figured it was the gimbal bearing which was original or more likely the universal which was also OEM original. Since it's a bit long in the tooth I get the bearing , universals and complete set of bearings and races and seals for the alpha's upper. I pulled the cap and it was just getting there on the top bearing surfaces so all new. Once into it I see that I'm not going to want to deal with those torque specs so hand it over to my neighbor who is a boat wrench.
Long story short all done Gimbal was actually fine and so were the universals but nuts on it 25 years is plenty old so money well spent anyways. Unfortunately I still get that shucking sound. so whatever it was / is wasn't related to the drive itself. Since then I got a nice stethoscope and started snooping around as best I can. Nothing up front, valves bearings pistons all sound fine but the noise is still in the back someplace. So the drive and shaft are fine, the engine alignment is spot on and there is no change in pitch if I nail it beyond RPM so it's safe to say the motor mounts aren't walking around besides I have kept the boat in a barn so nothing back there got water soaked like many.
Anyways today I decide it's time to take a serious look back there but it's about as cruddy as most peoples that old. I gunk it all down on the back hull area and carefully peel the crud off and flush the bilge with hot water repeatedly. While doing this the tip pops off my washer so I need to get the magnet out . While fishing around in the bilge the magnet comes up with a fair bit of steel filings. I guess maybe an oz worth all told. Lots of black gunk down there too which I couldn't identify. I haven't drilled a piece of steel in that boat since 2000 so it has to be recent. So now it's all nice and shiny as I wait and watch for what shows up down there the next time I use it .
I am thinking coupler breaking down . The boat handles normally in all respects aside from the shucking sound. At idle it makes that Topakata sound like an old hit and miss engine and as speed increases it is more like the sound of a weed wacker string at speed. No louder just faster and there. and no rubber stink. When I had it out last week with the doghouse off I thought I caught a faint quick rubber smell but it was gone as fast as it came instantly. Until something goes further I am just going to keep watching it very carefully for any sign of whatever is rubbing. So is there anything else back there that can go out, I looked at the schematics and diagrams and can't see anything, just coupler. I'm thinking after I use it a time or 2 there are gonna be more gunk and a few filings and an enginectomy is in my immediate future.
Long story short all done Gimbal was actually fine and so were the universals but nuts on it 25 years is plenty old so money well spent anyways. Unfortunately I still get that shucking sound. so whatever it was / is wasn't related to the drive itself. Since then I got a nice stethoscope and started snooping around as best I can. Nothing up front, valves bearings pistons all sound fine but the noise is still in the back someplace. So the drive and shaft are fine, the engine alignment is spot on and there is no change in pitch if I nail it beyond RPM so it's safe to say the motor mounts aren't walking around besides I have kept the boat in a barn so nothing back there got water soaked like many.
Anyways today I decide it's time to take a serious look back there but it's about as cruddy as most peoples that old. I gunk it all down on the back hull area and carefully peel the crud off and flush the bilge with hot water repeatedly. While doing this the tip pops off my washer so I need to get the magnet out . While fishing around in the bilge the magnet comes up with a fair bit of steel filings. I guess maybe an oz worth all told. Lots of black gunk down there too which I couldn't identify. I haven't drilled a piece of steel in that boat since 2000 so it has to be recent. So now it's all nice and shiny as I wait and watch for what shows up down there the next time I use it .
I am thinking coupler breaking down . The boat handles normally in all respects aside from the shucking sound. At idle it makes that Topakata sound like an old hit and miss engine and as speed increases it is more like the sound of a weed wacker string at speed. No louder just faster and there. and no rubber stink. When I had it out last week with the doghouse off I thought I caught a faint quick rubber smell but it was gone as fast as it came instantly. Until something goes further I am just going to keep watching it very carefully for any sign of whatever is rubbing. So is there anything else back there that can go out, I looked at the schematics and diagrams and can't see anything, just coupler. I'm thinking after I use it a time or 2 there are gonna be more gunk and a few filings and an enginectomy is in my immediate future.
