I have thought the same as bobw ,drilling a hole through the side of the swivel bracket ,so i can get some lubricant way down in the middle of those inasscessable inner threads . I use a 50/50 blend of power steering fluid and acetone instead of PB Blaster etc. It works real well in my experiences, along with several many heating and cool cycles with a propane torch. I am not saying the other aerosol lubricants are not any good, just prefer mine.
bobw’s comment about once the screw starts to move, moving it back and forth in bigger arc is a very good method. Even though it has begun to move ,i still apply more lubricant and heat, taking my time. BE PATIENT, don’t rush it or you very well may break the bolt off. mas spent a month working to free his clamp, can’t say i have spent that many days on it! It’s not like we have to drive it to work tommorow.
frankr’s comment on the transom bracket and screw both being aluminum and expanding and contracting at the same rate is good to keep in mind,
Many different approaches to this issue.
All of these responses have merit. Keep them all in mind and take your time.
"Some people want to know how a watch works, others just want to know what time it is"
Robbie Robertson
