Need reverse fixed 1978 Ford LTD II

This can be the valve body sticking but there is a servo that needs to be check as well here are the basic instructions on how to check the linkage and reverse servo. =

External Linkage and Manual Lever Check

Tools:

1 Assistant in driver’s seat
2 9/16” wrench
3 Penetrating oil
4 Small pry bar

Procedure:

1 Chock rear wheels, parking brake on.
2 Have your assistant shift through the gears while you watch the manual lever on the driver’s side of the transmission.
3 Verify it clicks firmly into each detent.
4 Manually move it to the full “R” position.
5 Check for free play or worn bushings in the rod ends.

Adjustment:

1 Put both the column shifter and transmission lever in Neutral.
2 Loosen the linkage adjustment nut.
3 Align rod and lever holes; tighten nut.
4 Verify full range engagement.

Before pulling the transmission, remove the valve body and inspect the reverse servo (round cover near tailshaft).

If its piston seal is cracked or the servo bore has fluid leakage, that’s your problem - and you can often fix that without a full teardown.

Please upload an image or short videos in your response of the problem, so we can see what's going on.