Cracked lower unit

[Jimmy]

I have a crack in my lower unit along the bullet. The crack is vertical. I had it welded once and the first time out after the repair it opened right back up again. I'm going to try and have it welded once more. My question is, does anyone know what could be causing this crack? Thanks in advance for any help!

Jimmy

[Valv]

Jimmy, there are few possibilities.

Unit had moisture in oil and froze up during winter time, causing expansion and crack (very common).
Also could be some internal gears are worn out and causes to "expand" or run out of alignment during usage and crack unit.

Unfortunately once there is a crack, it's seldom fixed by just welding it back, it it continues it has to be torn apart and/or replaced.

Sorry for the bad news.

[musky hunter]

Cracks sometimes can and cannot be repaired by welding. If welding penetration is not 100%, the remaining crack can propagate through the weld like it wasn't there. This is likely what just happened to you're lower unit. The chance of a successful repair after the first one failed is now greatly reduced. If you do a repair, make sure that as much of the original crack can be ground out as possible, preferably with a "V" shaped groove. But filling a large ground "V" may introduce an unacceptable amount of heat and stress back into the metal, stress which may cause warpage or another crack. It might be worth another try by a very experienced welder, but don't get you're hopes up too much. You could be throwing good money after bad.

[Jimmy]

Thanks for the replies you guys. Actually the crack after the repair went around the weld in a crecent shape. I'm wondering if the aluminum was weekend after being welded causing it to crack around the weld? I think I'll take it to someone that specializes in aluminum welding and see what they can do. Thanks again!

Jimmy