Loose engine mount

[markrinker]

Found a nut had backed off on the starboard aft inside motor mount nearest the alternator. Inspected the other seven mounts and they all look tight and no signs of shifting like this one.

I am baffled by this...how on God's green earth does a nylock nut back off this much? Anyone else experienced this?

 

[MasterFab]

They don't - very likely, someone left it loose after working it. The insert looks to be in good shape, but even so, I would replace it, then perform a shaft alignment check.

Dale

 

[markrinker]

They don't - very likely, someone left it loose after working it. The insert looks to be in good shape, but even so, I would replace it, then perform a shaft alignment check.

Dale

Is the alignment something a shadetree mechanic can do? It appears to have been walking side to side. The other end hasn't been moving - can I just tap it back to parallel and retighten as a starting point?

I discovered it at the end of the last trip so instead of diving in, took these photos and planned to address it next weekend up, before the big trip August 17th - 31st. Obviously, I want to have it dialed in before that...

 

[fwebster]

The second engine mount photo shows wrench marks where it has been loosened and tightened like an alignment has been done, but the first photo does not. Nylon insert lock nuts don't loosen themselves so my guess is that thar engine mount hasn't ever been tight. The nut under the mount is the one that controls where the engine sits, and therefore the alignment. You can tighten that nut until you can get both engines aligned, but all indications are that your boat may never have been aligned, so it is something you should do reasonably soon.

Aligning the engines isn't a technically challenging task, but it needs to be done by someone who has done it before. In the hands of a blacksmith, a pry bar and a big wrench can turn into an exercise that cakes hours and hours as he over-corrects then corrects the engine position. My last one was done after a transmission replacement and it took about 15 minutes to break apart the coupler, check the spacing, move 2 of the engine mounts, recheck the spacing, then reconnect the coupler on the side where the transmission was replaced....the other side took 10 minutes.....but I've done this a few times. Bottom line here is that this doesn't have to be a big expensive job, but it sure can turn out that way.

 

[markrinker]

The other three mounts show no sign of slippage or movement. If I were to tap this mount back in place and tighten until I locate someone experienced in alignment, would the boat be okay to operate?