If your lift goes in pulses, it is probably the pump. Mine is doing this which I know one side of pump is leaking. You can go online and find rebuild kits for it quite easily.
As far as over full on oil, biggest concern on them N's is axle seal leaking and contaminating your breaks.
Also, cylinder for 3 point maybe leaking excessively. Open one of the round covers at your feet, and watch for signs of this and, what looks to be air around pump.