So i have 2008 3520 hydrostatic with cab and have been experiencing a problem with the rear pto.
Was using my NH teader rakeand noticed it was slowing down and almost stopping on rough ground.
The rake does not have a clutch so it looks like the pto clutch is slipping.
I have not done any more...
I will add to the comments.
You have an expensive piece of equipment so why go cheap on lubricant and filters.
I always use the John Deere oils and filters.
Have to do a hydraulic oil change with 2 pails of oil at $136 each in Canada. Ouch
I have a 3520 and bought a Faza spreader which I believe are made in Italy
very good quality.
I also wanted control from the cab but all these spreaders have leaver which you have to reach back to operate.
I had to get creative and build my own control which is operated with a switch in the cab...