1999 Ford F150 repeated changes from high gear to a lower g

i own 97 f150 w/ same issue. (i'm no mechanic)

i had to lay on drvrs sidefloor with my head rested on brake/ acc pedels. looking up, i found that shifter mounts above steering column, a few screws had become loose. they were TORX drive.

removed 1 at a time, applied loctite, and drove back in.

this fixed a few problems,

Loose shift selector resulting in:
-Wont start (truck didnt think it was in park)
-Wont shift into OD (now it does)

my indicator is still misaligned, but at least i have all gears and can start her.

I have learned that a faulty Manual Lever Position Sensor could be responsible of the shifts. How I electronically test the sensor?

I just installed the Sonnax Main Pressure Booster sleeve and Regulator valve, By Pass Clutch control plunger, the O-ringed end plug of the 2-3, 1-2 shift valve, added a retainer to the Solenoid Pressure Regulator Valve. New OD servo, Reverse servo, 1-2 accumulator piston and springs supplied by Factory Tech (Gregg Evans) and the 2-3 accumulator piston without spring. Installed also the Factory Tech separator plate B.

Committed the mistake of not taking care to fit the OD Servo pin in the band, and has no OD. So I need to tear down everything.

I asked Mr. Evans several times why hole #11 is missing in his plate but received no response. I sent an email to another gentleman in TCCOA but no response either.

Can you send me a drawing showing the ID of all holes of the separator plate?

After having learned about the J-mod, and other instructions posted on forums, I concluded the following could be made to the original separator plate:

Hole #1 – no drill
2- 3/32”
3- no drill
4- No drill
5- 5/64
6- open to gasket slot size
7- 5/64
8- no drill
9- 1/8
10- 5/64
11- no drill
What you say about it? However, I preferred to keep my plate and install the one from Gregg.

Any comments will be very, very, very appreciated. I am a rookie on this of course !!!
The tranny has 109 K miles. No codes, Erratic 3-4, 4-3 sometimes and 3-1, no blinking OD light. Made neutral two times at stop, and suddenly engaged in first hitting hard. – These were the symptoms.