jerking clutch pack

[ledford]

I have a kabota L35, around a 2000 model. when using the shuttle shift forward or reverse, engagement of the clutch pack is rough, not smooth, causing tractor to jerk, especially after it it warmed up. I changed the fluid and filter last night, and lit didn't help at all. the longer I run it , the worse it gets.Does anyone have any ideas or had this problem before?