Dennis;
Glad you posted the photos that showed you were using a lift vs. trying to raise the boat with a jack while still on the trailer. It shows you were using your head. Thanks.
Folks,
I have seen too much in my life time and even tried everything before anyone has posted here personally and as a dealer. I have and will always discourage suggesting to lift the boat with a floor jack, blocking it on the bunks and so forth just to get the centerboard or even a regular metal swing keel off or on while on the trailer BECAUSE IT IS DANGEROUS AND I HAVE SEEN MUCH INJURY TO INCLUDE MYSELF. In addition many folks are not experienced enough. If you insist and get hurt, I told you so.
As for the 240, it too uses the 7/16 inch line only and after replacing it usually cures the problem but adjustment must be made so you will the klunk sound when going up and down. I am asking for further information and will post if anything else is of importance.