Glad I looked

Nov 3, 2018
82
Cape Dory, Albin 300ms Motorsailer, Vega Baltimore
So I’m down at the boat running some new wiring for the pressure water pump and look down in the engine drip pan and see a big bolt, obviously off of the engine just laying there. I look around some more and see another! Uh oh, not good. A quick scan of the engine revealed two missing bolts from the prop coupling- mystery solved. Still two bolts shaken loose makes me think there is an underlying issue, maybe misalignment but I haven’t noticed any unusual vibrations under power. Any suggestions? Needless to say checking the prop coupling will be on my prestart checklist!
 
Jan 7, 2011
5,714
Oday 322 East Chicago, IN
When I changed my prop shaft, I was taking a video of the coupling removal, and On camera noticed 2 of the bolts were out...just like yours.

i chaulk it up to poor maintenance...mine and the PO.

A couple of years now on the new shaft and coupling, and I check the bolts periodically and all is well.

Greg
 
Dec 14, 2003
1,442
Hunter 34 Lake of Two Mountains, QC, Can
Ditto on my boat a few years ago, only in my case I heard a stange clunk when putting in reverse. So I put her in neutral, no clunk. Forward, clunk. Reattached her to the dock and investigation revealed all 4 bolts were loose. Realized they had been loosened and retitghtened several time over a period of years for different reasons. Replaced them and the lockwashers. Everything has been fine since.
 

HMT2

.
Mar 20, 2014
900
Hunter 31 828 Shoreacres, TX
Similar issue on my boat, put some semi permanent threadloc on it, no problem since.
 
Dec 27, 2012
587
Precision Precision 28 St Augustine
You guys are scaring me. I’m going to check mine today. Thanks for sharing.
 

RoyS

.
Jun 3, 2012
1,742
Hunter 33 Steamboat Wharf, Hull, MA
Suggest using nylon insert lock nuts.
 
Dec 25, 2000
5,947
Hunter Passage 42 Shelter Bay, WA
Suggest wire locking these bolts like on our boat. Prevents them from becoming loose due to vibration or improper installation.
 
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Nov 3, 2018
82
Cape Dory, Albin 300ms Motorsailer, Vega Baltimore
Thanks for answering everyone. I guess it’s a semi-common problem. I‘ll try the locktite.
 
Nov 3, 2018
82
Cape Dory, Albin 300ms Motorsailer, Vega Baltimore
I don‘t think there is room for a nut, but will check. Currently the coupling is held to the transmission flange with dead ended bolts and lock washers.