2590 power shift stall


I need some suggestions on the next step in diagnosing my power shift problem. I have always had JD 6030's however, I recently took a chance and bought a 2590 case from a jd dealer (7000 hrs) . They are rare in south GA. I used it on a flail for 100 acres and everything
was fine with the transmission until now. It is a clean tractor with a good engine and A/C. Overall I have liked the tractor. Recently, it stopped hard and was jumpy upon moving then it went back to working. Now it
loads the engine in low range and stalls immediately in reverse. It does not load the engine in intermediate and high range; however, the trans oil light comes on in int and high range. It will grind gears and move in all forward gears. Stalls immediately in reverse.

I have changed trans filters. I have removed and polished each spool in tcv. I even removed entire tcv valve to replace the gaskets on each side. I replaced orings and checked all the valves and spools cleaning valve thoroughly. Each spool moves freely. I have IT manual. Not a lot of
mechanics that work on older cases here. Also the steering, pto, and remotes seem to work fine.

Any suggestions would be appreciated.

Update on symptoms: It will drive in intermediate and high;however, the light stays on and the lift fails to work. It will steer in these ranges.

Do you have a service manual? I have a 2870 and bought a service manual. In the manual there are very detailed procedures for checking the power shift (and other hydraulic) pressures, etc.

If you do not have a manual I will check in mine and see if I can pass on a few ideas from the 2870 service manual.

Good Day,
JP.