Case 1845c bucket tilt cylinder sticking

Was running a case 1845c skid steer and the left side bucket tilt cylinder started moving slower than the right which caused it to twist and bend the mounting plate. I took the plate off and disconnected the cylinders from each side on the rod ends. When i operate the tilt up and down the right cylinder rod extends fast and smooth but the left goes fast then slow then fast again like its sticking or something. It's still got full power but since they move at different speeds its completely screwed up the plate and that's another headache I'll deal with after i get the cylinder problem resolved. I'm thinking something on the inside is messed up? Theres no leaks on the outside seals or lines that i can see. Could it be air inside or a shortage of fluid? Looking at the sight glass for fluid level it is showing about an inch out of about 4 so it is probably a little low but i didn't think that would be the problem. I dont see any damage to the outside of the cylinder and the rods not damaged as far as i can tell. Any ideas or anyone with similar experience?