Ever since i have had my 580SL series 2 the side cutting edges would not stay level when raising loader bucket.It needed to be rolled back to be level.I got my service manual out and lengthened the cable under the "how to adjust anti rollback" After turning the clevis nearly all the way out i got bucket to stay level.Now when you have bucket all the way down and digging and when you roll the bucket all the way back it curls all the way back and loader joystick detent sticks and does not kick out on it's own and this causes engine to labor.
I'm not sure I fully understand but your lever is held in that detent position by a magnet until an electric switch is turned off when your bucket becomes level. If your switch is stuck on you will experience that symptom. On my Deere that switch is located at the right boom pivot pin near the windshield. Don't know about your Case.
Thanks Deon,I adjusted the return to dig switch yesterday and it fixed my problem.
Glad I could help and thanks for letting us know what you've found. That's how we all learn how to fix things.