Rock Damage

[nuffsaid]

One week ago today while on the first day of a Canadian fishing trip I hit a hidden submerged rock with my 2008 Merc 50 elpto while running at 4000 rpms and about 18 mph following a smaller boat in our group. I radioed my buddy for help and quickly swapped out the prop to no avail. He towed me back 20 miles to the fishing lodge we were staying at and I dropped the lower unit. Drive shaft snapped off at the splines, stub of the splines still in crank. Several big chunks out of the upper part of the skeg, lower cowling that holds steering rubber bumpers broken on one side. I have insurance, thank goodness, but what should I be looking for? My thought is a complete new lower unit and new cowling and new prop. Any thoughts? Is there a chance that the crankshaft is damaged?

 

[nuffsaid]

Re: Rock Damage

Well, got the estimate to repair my motor 3942.00 by boat shop. Insurance is sending me a check. Since I am a mechanic by trade, it doesn't make sense to me to pay the boat shop to do the repairs. I think I can pocket close to 2000.00 by doing the work myself. I know the power head has to come off to replace the cowl, just looks to be time consuming. Anything I might be missing?

 

[schematic]

Re: Rock Damage

No one can tell the repercussions of such an event. Hair line cracks or misalignment's can come back and haunt you at a later date. I would get a used gear case and take a gamble.

 

[nuffsaid]

Re: Rock Damage

I will go and pick up my boat this weekend. I have parts on order including a new lower unit and lower cowl, gaskets and a repair manual from mercury. I plan on indicating the crankshaft before I get too far into the repairs, but from what I have been told, the drive shaft splines are the week link. When I had the lower unit off a couple weeks ago to inspect the water pump, I found that the splines were already twisted slightly, probably from the rock that I hit on the same lake last year. That hit only cost me a prop and the hit was barely above idle. I will probably have to pull the broken splines from the end of the crank shaft, but that shouldn't take too long to drill and tap and pull it.

 

[Toddboat]

Re: Rock Damage

curious... was it an SS prop? They don't give. If it were a composite prop, there would prolly be no damage to the inner workings of the LU. Skeg would still take the hit, though.

 

[nuffsaid]

Re: Rock Damage

It was an aluminum prop. Upon further inspection, the prop output shaft is also bent. Good thing I got a whole lower unit coming.