G'day Cary on my "A" push up main there is a small rubber block that you squeeze in when you put the top catch shackle on (Whatever thats called). You have to put the rubber in just the right spot. There was an earlier "A" thread that showed a photo of it but I cant find the thread. I'll try to drag my main out today and take a photo. Can you post a photo of your current arrangement?
regards