3-point problems

[Wickedskygazer]

First off I'm new here, and semi new to tractor mechanics, but I do have a machinery , and auto background. I've got a Massey 135 with the 3 cyl diesel and 2 stage clutch... This past weekend I had the box blade on the back and was clearing snow when I noticed it was starting to float a bit, so I adjusted the draft and went on... Shortly later it was doing it again only this time it didn't respond to either the draft or control levers and rose to the upper position and now won't lower unless the clutch is pressed or the tractor is shut off. But as soon as the clutch is let out it's back up.

I was able to track down a tech manual on it and have been doin some homework, is it possible that I could have knocked the control spring assembly on the upper link bar out of kilter, If so could it be causing my problem. Any help would be greatly appreciated. Since then I have gained another foot of snow in my drive and can't get my truck out (it only sits about 4 in high) thanks for your help