Boat is 1989 Chaperral on Shorlander trailer. Springs are rusted, 6 spring and have some breaks in them. I took them off and front is an eye and rear appears to be a "C". Length is 26.25 middle of eye to middle of "C". There are no shackles and they are bolted directly to a welded part on the frame. I have nobody in my area who can answer the following question for me. When they are installed, what keeps the "C" from slipping off the rear bolt? Do they have a bushing too? Do you tighten them tightly or loosely so the open part can move? Tia.