Help alpha one drive

[Rspillman88]

I have a 1994 bayliner capri 1850 with a mercruiser 4.3l and alpha one gen 2 drive. I'm getting a loud knocking noise and I traced it down to the gimbal area so I pulled the drive and when the drive came off this pin fell out of somewhere on the drive side. I can not find it in parts diagrams and cant figure out what it is and where it goes.

 

[Rick Stephens]

Pivot pin for an exhaust shutter?

 

[Rspillman88]

Pivot pin for an exhaust shutter?

That might be very possible because I noticed that the exhaust shutter is just loose in the transom assembly. How do I get it back in or what should I do?

 

[Rspillman88]

Also, the exguast shutter was all the way down in the bellow, which I dont believe is right

 

[Rick Stephens]

The shutter(s) is probably toast. Probably need to replace both. They sit at the top of the Y pipe under the rubber connector.

Loud knocking is probably u-joints.

 

[Rspillman88]

The shutter(s) is probably toast. Probably need to replace both. They sit at the top of the Y pipe under the rubber connector.

Loud knocking is probably u-joints.

Okay thanks for the info, would you happen to have a pic of the toll of that y pipe. I will check and replace them, also when i took the drive off the u joint below is shot and it was full of water and the gimbal bearing feels gritty. I checked the u-joints for play and found none but I will probably replace anyways while I'm in there.

 

[Rick Stephens]

I found a picture someone posted on this forum. And yeah, if you have knocking, replace the u-joints. If there is anything in the gimbal bearing, replace it too.

 

[wahlejim]

You may also want to check into why the shutter failed. It is possible they fail overtime, but those tend to be one of the first things to go in an overheat situation. The most common culprit is the water pump impeller. You may want to change that out while the drive is off and you are doing work on it anyways.

 

[Rspillman88]

I found a picture someone posted on this forum. And yeah, if you have knocking, replace the u-joints. If there is anything in the gimbal bearing, replace it too.

Rick, thanks so much man and yes I'm going to be replacing the u joints as well when I'm in there.

 

[Rspillman88]

You may also want to check into why the shutter failed. It is possible they fail overtime, but those tend to be one of the first things to go in an overheat situation. The most common culprit is the water pump impeller. You may want to change that out while the drive is off and you are doing work on it anyways.

Jim,
That's kind of what I was figuring. Although my parents gave me the boat, they've had it since new and I dont recall an overheat situation but I am going to do the impeller while I'm in there.

 

[achris]

The old shutter design had the pin wear through. No overheat required. Go in the stickies and find an article I wrote on all the exhaust shutters. That'll explain it all.

Chris. ....

 

[Rick Stephens]

If I was going after the shutters I would plan on taking the exhaust elbows off the top of the manifolds. That way I can inspect the elbows, which tend to erode away. And since they are double wall, they then tend to leak. The only cost is the two gaskets, make sure you get the metalized ones and not aftermarket paper. Clean up to perfect, even run a flat file over the surfaces before reassembly. Taking apart the exhaust down to the Y pipe is a snap with the elbows off.