Volvo Shifter Failure
All is not gold that glitters. Before converting I recommend one checks out the potential failure mode.Last summer I was helping a couple dock their Beneteau that had a single lever throttle-shifter and they were trying to get into a tight space behind a large power boat. I had one of the bow lines and they were manuvering into position when they shifted into reverse and nothing happened - the boat kept going forward under power headed straight for the stern of the Ocean Alexander.I was able to throw the line around the cleat and stop the forward motion just feet before things would have got expensive. The stern started to swing out and another guy on the the dock was able to grab the stern line and throw it around a cleat. The owners got the engine stopped and that evening we took things apart and found the problem. The shifter was a Volvo shifter and apparently a metal part in the shifter deformed and couldn't push-pull the cable enough to cause the transmission to change gears. The same failure compromised the throttle and they couldn't change the engine speed. We also found signs that the shifter had been "worked on" some time previously due to the same problem.The Volvo single lever setup has a lot of sliding arangements which put a fair amount of stress on the components parts. The failed part was stamped out of heavy sheet metal. The failure was at one of the bends in the metal. Thicker metal or a casting would probably have prevented this failure and/or perhaps better lubrication. There was a lot of metal shavings indicating metal-to-metal wear.Since the discussion is about an Edson system, I know they put out a good steering maintenance paper and with any system the manufacturers recommendations for maintenance, including inspection and lubrication, should be followed. Unfortunately for the Volvo situation, the unit is very difficult to access and, frankly, my Edson helm (two levers) isn't a heck of a lot (if any) better.The couple had only owned the boat for about a year and this was all new to them. Also, their engine shut-off was inside the boat in a hard to access location.Hunter dual-lever setups aren't immune to failure either. My Hunter has the shut-off near the helm and I had a gear shift failure a couple years ago. The screw in the gear shift lever sheared and I lost the ability to shift - also while docking in a similar situation. Fortunately I had a lot of help with the lines and was docking at idle speed when the failure occured so there was no mishap. Replaced the screw and everything was fine.The good thing about a two-lever system is only one thing can fail at a time.