Broken Pivot Pin Lock Bolt

Kenepela

Seaman Apprentice
Joined
Jul 19, 2009
Messages
31
Twin Volvo AQ131D with SP-A outdrives. I finally decided to tackle taking off my outdrives to replace trim hoses, u-joints and bellows. I've had the boat for almost a year now, after watching it sit in my neighbors yard for about 8 years. On one of the outdrives, both pivot pin locking bolts are corroded in (everything looks clean on the outside but corrosion on the inside, aluminum/stainless). I broke the first one off at the start of the threads in the threaded part of the transom shield, so it's about an inch inside the hole from the outside(hopefully it makes sense). How am I going to remove the broken part of the bolt, thought I would ask before I try drilling this stainless bolt to extract it. Should I even try this or should I remove the transom shield and take it to a machine shop or someone with better knowledge and tools, besides a hand drill. I'm really afraid of messing up the threads. Any advice for removing the other one, without breaking it off? Is it ok to heat the transom shield? I tried spraying penetrating oil, but I don't think it actually reaches the threaded part, where it's needed. Thanks again!!!
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Broken Pivot Pin Lock Bolt

There is no easy answer. If there was enough corrosion to hold the bolt and you broke the bolt, you can bet money an easy out is NOT going to work. Carefully drilling and re tapping is the only way to fix it.
Good luck, I know for a fact that it's easier to say than do.
Start by using a QUALITY drill bit the same size as the hole and slowly and carefully making the center of the broken part.

On the other bolts, before you break them, use plenty of heat (oxy/act not propane) to quickly heat the alum. around the bolt, and loosen the bolt. If the bolt gets too hot, let it cool before trying again.
 

Kenepela

Seaman Apprentice
Joined
Jul 19, 2009
Messages
31
Re: Broken Pivot Pin Lock Bolt

Thanks Don S, but now I have managed to break off the other bolt, and it broke of near the top of the hex head, so it is still locking the pivot pin in place. I haven't gotten a good drill bit yet, will get one tomorrow when I go to town. My question now is, how hard is it to remove the transom shield, is it pretty self explanatory or does it get pretty technically involved? Aloha!!!
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Broken Pivot Pin Lock Bolt

Once you get the upper gear box, and the lower unit off the intermediate housing, get the engine out, and the Y pipe off, It's not a bad job to get the transom shield off if all the bolts aren't froze up.
 
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