2. Running Equipment

Note: I insert records as I come across good advice in current email threads or as I get a chance to review the archives. For that reason all elements of the index are not populated. If any C470 owner does the research and sends me text for a record, I'll include that with attribution. ...Joe

2.1. Transmission
2.1.1 Transmission to prop shaft coupling
Problem:
Loose coupling bolts.
Advice:
On the way back up the coast from Ensenada to San Pedro, the coupling bolts all sheared off and fell into the bilge space. Pretty scary; pitch black, high winds and heavy seas. Didn't know if the shaft was going to fall out and sink the boat. No way to hold the shaft in place while sailing back for 8 hours! Found out later after docking in San Diego that they were the wrong bolts and not the proper lock washers. I got some replacement bolts in S.D. and made it home safely. I now check the coupling bolts on a regular basis.
Owner: Mike McKean 
Boat: Sunset Moon; 30
Date:
15Dec09

2.4. Shaft seal / dripless bearing
2.4.1 Replacing dripless bearing.
Advice:
Shaft noise is created by the carbon wearing against the stainless steel collar. It is caused by the lack of water as a sealant and a lubricant.
  • I just replaced my bellows and carbon after 10 years and 1200 engine hours, it was still working fine but had worn down to the point that it needed to be replaced. PYI recommends replacing the bellows when it gets about 8 years old. If you replace the carbon you will get one that has a nylon vent/water fitting in it. On our boats all you have to do is run a vent line from that up toward the top of your engine compartment. If we were power boats we would need to plumb that into the seawater engine pump to force water to the seal. In our case all we need to do is create a way for air trapped at the front of the shaft log a way to escape.
  • To replace these parts you will have to haul the boat, disconnect the shaft from the transmission, and work the shaft back until you can remove and replace the parts and reinstall the shaft to the transmission. It will take two guys about 2-3 hours if you know what you are doing. When you remove/replace the stainless steel collar remove the set screws and lubricate the holes/o-rings with soapy water. DO NOT USE Petroleum based lubricants.
  • A shaft slide hammer would be a great help in pulling the shaft back the 15-20" you need. Also if you have a set of headsets like some folks have for anchoring they are a great help in talking to the person helping you under the boat.
Owner: Bill Martinelli
Boat: Voyager; 11
Date: 7 Dec 09

Problem: Shaft seal retainer
Advice:
Just make sure you put a stainless hose clamp around the shaft forward and right against the stainless steel hub as insurance against it ever
slipping forward. Don't worry about the hose clamp unbalancing the shaft. By the time you figure in the reduction gear of the transmission the shaft isn't spinning that fast.
Owner: Bill Martinelli
Boat: Voyager; 11
Date: 12 Sep 08

2.4.2 Shaft seal / drive train noise.
Problem:
Loud noise in drive train when engine is in gear.
Advice: It only made the noise when the engine/transmission was in gear. At first I thought I destroyed the transmission because when I slowed down and shifted into reverse I kept going forward! Then it dawned on me that I was going down river and was in a 4.5 knot current going my way. When I went into neutral - no noise - forward or reverse - noise! Boat still went forward, still went backwards, what the hell maybe the current caused me to lose water in the shaft log - Burp The Shaft - Burped - NOISE GONE!
Owner: Bill Martinelli
Boat: Voyager; 11
Date: 9 Dec 09

Problem: Shaft seal noise
On occasion there is a terrible noise from the engine compartment.  It sounds like a 1955 Chevy push button starter that is engaged while running and grinding against the flywheel.  It occurs at all R.P.M.  I immediately put the shift into neutral and the noise stops.  It occurs once a year or not at all. [Gary Girard, Goddess; 4; 20 Nov 2009]
Advice: My bet is it is your dripless shaft seal is making the noise. Same thing occurred in our C-36. Based on your hull number I think your boat doesn't have the water injector on the dripless shaft seal. Without it you will get air in the seal causing a bad grinding noise.  Burp your dripless shaft seal frequently, especial after the diver does your bottom (Air Bubbles) and it should go away.
Owner: Tom Jeremiason
Boat: S/V Camelot; 145
Date: 20 Nov 2009

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