Mule Drive on my 128 is not level

[zooyorklp]

Like I said my Mule Drive on my 128 is lower on the left side than it is on the right side. I'm assuming this is why I'm not getting an even cut. When I'm mowing it seems that right after i mowed a certain spot that the grass is a lot higher on the right side. It even cuts all the way to the dirt in some areas due to the left side of the pto being so uneven. I've done some research and it seems like it could be the J bolt or whatever its called and or the spring on the J bolt. On the right side of the mower the bolt goes through the hole between an inch or two but on the left side the J bolt only barely goes through the hole probably about 1/8 of a inch. Here's a pic of both sides.
Here's the side that seems to go all the way through



And here's the side that doesn't seem to go all the way through



Now when I look at the spring on the J bolt, on the side of the pto that seems to be too low, the spring looks very old and one end of the spring is bunched together instead separated. Here's a pic.
Here's the pic of the spring I "think" is good.



Now here's a pic of the spring I "think" is no good.



So I'm curious about what everyone thinks and if yall think my problem is either my J bolt and or spring.


Also....

This little part keeps coming undone. I assumed it was because the pto is not level and was hoping if i fixed the J bolt that this would stop coming undone.


I'm only 21 and this is my first garden tractor so I'm new to all this. Thanks for your time hope somebody can be helpful!