Help! Stuck bolt on Rotax Gearbox

Brian Jackson

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Help! I'm attempting to rotate the gearbox on a 503 180 degrees and have encountered a frustrating problem. There are 2 bolts that mount the gearbox enclosure to the engine, and they were torqued very tightly. The bolt on the right will not break free. I even used an impact wrench until it started to round over the bolt head, so I stopped until consulting the forum.

What I noticed is that there's a little cut-out in the bearing boss for bolt clearance, which was sufficient on the left bolt to accommodate the slightly thicker socket for impact wrenches. The right cut-out is not, so I can't fully seat the socket over the bolt head. Regular sockets clear the head, but I can't get enough arm leverage to break the bond. Any ideas from the group? Thanks in advance.

Regards,
Brian Jackson
 

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Use a six point regular socket on the impact wrench. If it rounds off drill the head of the bolt off, remove the gearbox and vise grips to remove the bolt shank.
 
Brian, first try Jeffs suggestion using a 6 Pt socket. If that is unsuccessful see if any of your buddies has a set of Grip-title sockets. I have removed some severely rounded
bolt head with them. Also, heat the bolt, and let it cool. Sometimes the expansion and contraction will reduce the friction on the bolt and allow it to turn. Finally, as Jeff suggest, drilling out the bolt head should allow you to remove the case.

Good luck,

Dave
 
No Title

Success. I used the thinner, 6-wall socket designed for a ratchet, mounted to the impact wrench. I had to run out and purchase an adapter to make it work with the 1/2" square driver pin. Was worried the socket might shatter but as the photos show, worked well. Thanks guys for the tips. Even though I didn't have to use most of them this time, I learned some new things from a relatively simple task.

Respectfully,
Brian
 

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Excellent, Brian. Always a feeling of relief when you don't have to resort to extreme measures. Just another hint. Don't forget to also try something like PBblaster. I have had it lossen bolts that I were sure were never coming out! Just give it time to work. I was out in the garage digging around in the toolbox
and found another type of bolt extractor made by Erwin. These actually work much better than the Grip-tite sockets.
 
I highly suggest you use the CALLED-OUT Locktite product when you put them back in! The difficulty you had getting them out was FOR A REASON. They
were not just torqued tightly. They were installed with a semi-permanent or permanent thread-locker. The stakes are high if they come loose in flight. I would even
get two new bolts from Lockwood because you MAY have twisted the shanks almost to the yield point, getting them out.
 
bryancobb;n1120134 said:
I highly suggest you use the CALLED-OUT Locktite product when you put them back in! The difficulty you had getting them out was FOR A REASON. They
were not just torqued tightly. They were installed with a semi-permanent or permanent thread-locker. The stakes are high if they come loose in flight. I would even
get two new bolts from Lockwood because you MAY have twisted the shanks almost to the yield point, getting them out.

Hi Bryan.

Yes, agreed 100%. I will consult the manual and call Rotax Rick (whom I purchased the engine from) to verify exactly which LokTite to use, and replace the bolts with identicals. Thank you for mentioning this.
 
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