F40/40 driveshaft coupling

[Laisve]

Hello Freedom lovers,
I am trying to replace the bolts in the shaft-transmission coupling. The bolts got shorn or loose, and the shaft became uncoupled from the transmission last season while motoring in a heavy chop. We did an emergency repair with soft bolts from Home Depot, as we were away from our home base, and it took a long time to replace the four bolts. But now the coupling is shedding the bolts again. I got the proper stainless steel bolts, but have a few questions about installing them:
1) Is it normal for the bolts to become undone over time? It happened in season 4 of owning the boat the first time.
2) Is using nylock locking nuts or regular SS nuts with spring washers better?
3) As the coupling is directly underneath the galley cabinet, is there any way to gain better access to the coupling? I assume the cabinet is not easily removable. I can only work one-handed, as I cannot squeeze in through the narrow access panel door. It took me a long time to tighten one bolt, using locking pliers on the head, and a 17mm wrench on the nut. No room to fit a socket wrench. The F40/40 access to the shaft coupling and cutless bearing is horrible. Any tips on how to make this easier are much appreciated!

[GeoffSchultz]

Laisve,

I used nylocks on mine. Make sure that the bolts are just long enough, as you don't want to spend any extra time tightening down a nylck.

Access to the coupling is bad and it takes a LONG time to tighten up the bolts. I've never found a good solution.

-- Geoff