Not being familiar with the shock set up on your trike, it is pretty near impossible to tell you what to do other than get under it and investigate your suspension. You need to get familiar with your rear suspension.
A little background for my fellow Veteran. I normally work on computers, mainly maintaining payroll systems. I started working on computers in the Marine Corps back in 1990 and can handle most issues that will arise with no assistance. This is my first bike. My father and Uncles were mechanics, but they have all passed away. I have no other family and although I ride with a club, none of them work on their own bikes. Therefore I consider this my best resource and so far it has not steered me wrong.
I have seen how a shock is changed, but I know nothing about how to check if it is a good or bad shock. That includes whether it is gas filled or the stock air shocks. The gentleman that I purchased the trike from has passed away.
There is absolutely no one here locally in Memphis that will work on a Goldwing Trike older than 2000. They either cannot accommodate a trike, only work on HD's or they do not work on anything older than GL1800's. I have someone several hours away that I take to for anything major, but I am hoping not to have to go there.
Therefore please bear with me as yes, I can go out and look at my suspension and get familiar with it, but it helps to have some guidance before I start taking things off to get where I can see everything.