If I can learn how to scan in my wiring diagram, I will attach the chart that is in the corner that has three columns - shifter position, wires energized, solenoids.
First line is Shifter position F1, wires energized - T6, T4, T5, T9 - Solenoid F,1,2,3
Second line - F2 - T6,T5,T9 - F,2,3
Third Line - F3 - T6,T9 - F,3
Fourth Line - F4 - T6 - F
Neutral is the same 1,2,3 solenoid and corresponding wire numbers plus a wire labeled AS which goes to power the start relay so the mashine will start when in neutral only. F and R solenoid not energized but the twisting gear selector still sends voltage to the solenoids.
Reverse is the same as Forward but the F solenoid is replace with the R solenoid which is wire T7.
All the wire numbers, and functions I have teste at many different places many times - they function as the wiring diagram and manual say they should.
Drained the fluid and pulled the sump screen - screen was very clean - if I could post a picture I would - almost nothing on the screen - what was there mostly looked like very small pieces of silicon, but I don't think it was. Nothing magnetic was on the screen. To me it looked like stuff that could have been in the original casting when assembled. Maybe 20 pcs in all.
But I pulled a dumb dumb - the high pressure filter I pulled the other night was the brake system filter - it was so clean and so irrelevant. It is very hard to see all the hoses under the cab. Even though the info I have shows a high pressure filter housing - my filter is a spin on - AND the damn thing is a Clark brand with a date of 98 - and I found a SN on the bucket with a 98 date on it so I feel sure that the machine is a 98 and the filter was original. Books say the filter has a bypass in it - wonder if the filter finally plugged, bypass opened, let some trash by and stuck a valve in the valve body and or the modulator body that I now have a picture of. Maybe a valve that lets fluid to the 123 clutches?
Unless someone sends me on a different path, next is removing the valve bode and modulator plates to do exploratory surgery and see if I can find some stuck or clogged valves or orifices