I have two terramites, over 24 hydraulic cylinders. Some are like problem children. I bought some cylinders form International Hydraulics for less than two rebuilds cost me at a hydraulic shop, $150. One cylinder I had to pay over $450 from factory because of the location of the ports I couldn't use an aftermarket cylinder.
Without seeing what you have, it's possible you may have a unique end on your rod and you will have to get a factory replacement.
I also found a hydraulic shop a few miles away where I can buy all the O rings I need to rebuild my cylinders for around $20.
When I have a problem child, a cylinder that I'm having issues with, I've discovered there is a cause and effect relationship between parts on the outriggers are worn out, stabilizers are not being held in position, putting a stress on cylinder, even cracking welds on cylinders.
Then I have cylinders that have yet to cause a problem. Then I discovered two cylinders leaking just sitting in cold pole barn.
Hope I've helped. If it's possible to use International Hydraulics, google them even call them, to get an aftermarket cylinder and get someone to weld a special end on it. Good luck.