Help with frozen lower unit bolt

[tedmcneill]

Please help me with the problem of a frozen bolt on the lower unit of an old 3 cylinder 70 HP Evinrude engine. The bolt is the rear bolt above the trim tab that is giving me an uncommon problem; at least uncommon for me. I can use a 24 inch 1/2" breaker bar and using all my muscle move the bolt an 1/8 inch counter-clock wise move, the bolt squeals loudly like the bolt is stripping the threads. I have turned the bolt about a 1/4 to a 1/2 turn with no change in the condition. My question, is should I keep on turning the bolt until it breaks or stripes itself out, or have I missed something very elementary.

I would have thought the bolt would have broke if it was entirely frozen. Or if frozen would have broken loose after turning the amount I have done. I tried both my torque guns 3/4 extended shank and my 1/2 inch with no success, they sit there.

A boat mechanic told me to heat the area with a torch while turning the bolt out. ?? For some reason this doesn't make sense to me. Hopefully someone in this forum can advise me one way or the other. I have used a torch on many a stubborn steel part to help assemble or disassemble, but never anything aluminum. Help please, anyone!

Thanks,
RvrBoatVet
Tu'An CovanMy '69-'70

"Life's tough......It's even tougher if you're stupid." John Wayne

 

[Haffiman]

Re: Help with frozen lower unit bolt

Use a propane torch on FULL blast, heat and unscrew the bolt.
Heat the alu, not the bolt.

 

[1946Zephyr]

Re: Help with frozen lower unit bolt

Spray a lot of PB Blaster on it too, to loosen it up.

 

[Chris1956]

Re: Help with frozen lower unit bolt

I like to heat 'em up and then spray the penetrating oil on them. In your case, work the bolt back and forth to work the oil into it. Hopefully it will unbolt. Normally using a breaker bar breaks the bolts, so be careful with that thing.

 

[tedmcneill]

Re: Help with frozen lower unit bolt

Thank you to all for your suggestions. Used the heat and penetrating oil, worked like a champ!!

 

[all duck'd up]

Re: Help with frozen lower unit bolt

dont put that same bolt back in! buy a new one and also PB blast the hole real good to get any kind of grime out if any

 

[garzilla]

Re: Help with frozen lower unit bolt

Throw a dab of anti seize on the new ones too perhaps.

 

[tedmcneill]

Re: Help with frozen lower unit bolt

All great ideas which I had followed. Additionally, as a general personal rule I always chase buggered up threads with a gh 2 or 3 tap to size.