Looking for a hydraulic system schematic for an aw71 trans, specifically the OD system. I have a problem with the trans in my 740 which I believe is the result of a stuck 3/4 shift valve, but would like to find a hydraulic diagram to see if I can figure out how the system works, and see if I can make sense of my problem. I am quite sure it is not an electrical or solinoid problem, and the evidence points to a stuck spool, possibly caused by contamination.

Also, has anyone had any experince with removing and cleaning a dirty valve body? I am hesitant to remove the valve body for free of causing more problems, since my experience has been that these things sometimes develop more problems if they're messed with. I am an experinced mechanic, so I am confident in my ability to do the procedure properly, just concerned that it may be something best not messed with. I currently have no OD, but everything else works fine, and I'd rather not mess with it if there is a high chance of it getting further messed up.
Thanks ~ John