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Crack in lower unit

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#1 No Slack

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Posted July 28 2003 - 9:45 PM

When I was putting my boat away yesterday I noticed a smear of gear lube on the lower unit. Close examination revealed a crack about an inch long in the housing below where the anti-ventilation plate is and towards the front. I have no idea how this happened. There is no sign of any impact, and I faithfully change gear lube before storing the boat for the winter. (engine is an Evinrude 88spl) Has anyone seen this happen before? To repair it I plan to drain and remove the lower unit, vee out the crack with a die grinder, and take it to a shop I know of that does welding on aluminum. Then I can grind the weld flush, repaint, and the repair should be invisible. Would anyone else repair it differently? This should be a strong, permanent repair. I'm just happy I found the crack before this became a major failure. I checked the area where the boat is stored and found no evidence of gear oil on the ground so I have to think this just happened yesterday.

#2 Kings over Queens

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Posted July 29 2003 - 5:22 PM

You might wind up having to redo the seals as the heat transfer from the welding could cause a problem. I had a similar issue with a crack and was advised to replace entire lower unit rather than mess with the repair.


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Posted July 30 2003 - 2:05 PM

My cousin hit a rock with his merc, cracked the lower unit worse than yours, had it welded and it was good as new, never had a problem after that. I'd go with the weld.

#4 onthefly

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Posted August 06 2003 - 8:56 PM

I had a dent in my lower unit on 60 hp evinrude. It also looked to have a small crack. filled it with a epoxy putty designed for automotive use sanded and repainted has held up.

#5 Michael P

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Posted August 07 2003 - 3:43 AM

No Slack,
What you describe is the best way to go about the repair you need to make. Additional homework for you though is to try your best to figure out how/why it happened to begin with. External impact, internal impact (broken gear?), faulty housing, electrolosis, inordinate cavitation, grossly unbalanced prop??? Lot's of things you cause this, especially if there was a sub-standard casting done when the housing was originally made. Good luck to you.

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#6 mako231

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Posted August 21 2003 - 8:33 PM

Did you store your motor for the winter tilted up? If you did water could have gotten in there and the freeze thaw cycle could have done the damage.