I couldn't agree more. My wife's operation has a CaseIH 5140 with power reverse and they darn near comes to complete stop before changing direction. I know it's meant to handle it without stopping but the tractor weighs about 12,000lbs by itself with weighs and fluids and that's lot weight just to be going along at 5 or 6 mph and jam it into the opposite direction.
Here is 4 links: 1) The link to online JD manuals, goes back to about 1999. 2) Link to 48 backhoe. 3) JDparts. 4) Sign-up for free and get parts availability and cost.
If you got a loader with your tractor link 1 you maybe able to find the manual
John Deere Ag - New Equipment: Technical Publications - Equipment Search
OMLVU13145_K5
John Deere - Parts Catalog
jdparts.deere.com/servlet/com.deere.u90.jdparts.view.publicservlets.HomeUnsigned