Join Date: Sep 2004
Thanked 28 Times in 19 Posts
Rep Power: 13
I had always prided myself in being one step ahead of maintenance issues. You know, "Fix it before it's broke!" But, then we took our cruise to Maine.
A few days into the trip I found a nut in the bilge below the engine. Paint on the nut indicated it was from the engine. Origin? Not immediately apparent. I got out the mirror and worked my way around the engine -- No joy!
A week later, during the morning engine checks I put my finger on the engine belt to test tension and the alternator moved. Cause: nut missing from the bolt that holds the alternator on. No, t'was not the nut found earlier. Repair was simple with a new nut from the spares inventory and a quick replacement of the old belt that had been worn badly by the loose alternator.
Several days later on the way back to Cape Cod we stopped for the night in Gloucester. After dropping the anchor into the muck of the city's harbor, I asked the mate to put the engine in dead slow reverse to set the anchor. In response the engine errupted in a metal-on-metal racket that sounded like a chain around the prop banging on the hull. A quick engine shut-down followed by a visual inspection of the engine compartment revealed that all four nuts holding the shaft to the gear box had come off. The noise was the gear box flange banging into the ends of bolts in the flexible coupling. No, none of these four loose nuts were of the size of the one found in the bilge earlier in the cruise.
We spent the next four hours removing the flexible coupling form the shaft and then re-attaching everything with as much torque that could be applied given the wrench that would fit in the space was only 7" long. In the morning we were on our way again.
So....my question for the mechanics out there is: What's your method for finding loose nuts before an alternator or shaft falls off? At what interval should one go over the engine to tighten things up? I had always figured that once the nut was properly torqued (and in some cases with a dab of Locktite applied) that one needn't worry, but my recent experience suggests otherwise.
Any advice in this area would be most welcome.
And I still don't know where the first nut came from! Fingers are crossed that it's not critical.