If it's a gear tractor, you have the range and gear selector mounted on the linkage shaft under the fender, it is prob. rusted or built up dirt.
Try this first put it in gear, then put the range selector in gear, but watch the shifters and see if the other shifter moves. if it does spray the shaft with PB blaster and work the shifters a few times to get them moving, usually this works. also under the fender there is a safty switch with 2 fingers with a tab from the linkage between the fingers, if it is off, just a little it will just shut itself down. you can re-ajust the safty switch so the safty work properly. it works the same way the safty switch works under the seat. when you stand up from the seat, it will shut itself down. thats where your problem is.
I had to do the very same thing on my old 1528.
Also you can see the safty I am talking about, just look though the shifter slot, and you will see the 2 fingered safty switch, by just looking down the shifter linkage.
Hope this helps
david
