crack in lower unit

[lilb]

I have a Omc King Cobra lower unit with a 6" long crack on the port side by the nose cone. I was wondering if you have to pull all the gears out to reweld it or if that is somthing u can do with it all togeather. Thanks. It also looks like it already had a nose job before i aqqired it.

 

[Bondo]

Re: crack in lower unit

Ayuh,... That'll depend on the Weldor you hire to Fix it....
I imagine they'll want a stripped,+ degreased case,...
The oil contamination would make it hard to get air-tight welds...
Aluminum is a very tricky metal to weld,... Properly...

I'd also Bet that it needs a Reseal job anyways,... The Crack was caused by Water in the oil...

 

[cr2k]

Re: crack in lower unit

If and that's a big IF the drive metal is not too porous it can be tig welded. If it a poor cast you may need to look for a new/used lower housing. But I would imagine it would need to be stripped with a crack that big. Also that big of a crack may cause an alignment problem with the dogs and prop shaft.

 

[lilb]

Re: crack in lower unit

Well thanks for the input guys and sorry it took so long to get a reply. I was wondering how much pressure it would take to crack that since i had it pressure tested before it put it on and it held pressure 14 lbs for 10 min or so the took the gauge off. Where else would the water come from?

 

[300sflyer]

Re: crack in lower unit

It likely had water in it from a leaky seal over the winter, and then froze. That is what would cause it to crack.

 

[lilb]

Re: crack in lower unit

Sice i forgot to mention i got the lower unit last fall and sat in the house over the winter when i first pressure tested it i foung the prop shaft seals to be bad. So those were replaced, then pressure tested it again and everything was ok. No crack in lower foot. So i put the grive on and ran the boat for about 1 hr on the lake to test it when Ipulled the boat out and brought it home and looked at it the next day was when i saw the crack. Just kinda wondering what happened. When i ran it i took it easy because I wasn't sure of it's current condition, and everything worked perfect no loud noises, clunking, grinding, or any thing like that and I also didn't hit any thing. and now im stumped on how it cracked could have been a bad weld to begin with.

 

[Bondo]

Re: crack in lower unit

Ayuh,.... How 'bout some Pictures....