I have a farmtrac 555 dtc and it mostly sat all winter and when I went to use it in the spring it's clutch was stuck but I was able to get it into 1st then shift up to 4th and once it warmed up the clutch started working again. Well now I went to mow and the clutch won't disengage the PTO. Would changing the transmission oil help or make it worse. Anything else I can try, I was thinking run it for a while to warm up but didn't want to break anything.