You have the 42rle transmission.
You may want to check out the shift cable before taking it to a shop. Just a thought, since the rest of the gears work thats probably not what it is.
DESCRIPTION
The Solenoid/Pressure Switch Assembly (Fig. 256)
is inside the transmission and mounted to the valve
body assembly. The assembly consists of four solenoids
that control hydraulic pressure to the L/R, 2/4,
OD, and UD friction elements (transmission clutches),
and the torque converter clutch. The reverse
clutch is controlled by line pressure from the manual
valve in the valve body. The solenoids are contained
within the Solenoid/Pressure Switch Assembly, and
can only be serviced by replacing the assembly.
The solenoid assembly also contains pressure
switches that monitor and send hydraulic circuit
information to the PCM. Likewise, the pressure
switches can only be service by replacing the assembly.
REMOVAL
NOTE: If the Solenoid/Pressure Switch Assembly is
being replaced, the Quick Learn Procedure must be
performed. (Refer to 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/TRANSMISSION CONTROL
MODULE - STANDARD PROCEDURE)
(1) Raise vehicle on hoist.
(2) Remove valve body assembly from transmission.
(Refer to 21 - TRANSMISSION/AUTOMATIC -
42RLE/VALVE BODY - REMOVAL)
(3) Remove Solenoid/Pressure Switch Assembly
retaining screws from solenoid (Fig. 257).
(4) Remove Solenoid/Pressure Switch Assembly
and screen from valve body (Fig. 258).
Its got pics but I cant figure out how to copy them. Im not 100% sure thats actually the solenoids. It keeps calling it a solenoid/pressure switch.