Sorry to hear it's still having problems. Couple of things to check. I would have thought the shop has done this already, but maybe not?
At the back of the drive, disconnect the shift cable from the linkage and try to push and pull the cable in and out. Should be less then 1/4" of play.
Next is to follow Volvo's procedure to check for the correct amount of stroke.
Measure and record the distance between mark and end of
casing.
3. Mark cable core wire at end of casing with control in the neutral
detent position.
4. Move the remote control handle to the wide-open-throttle position
in reverse gear to extend the shift cable. Push in on cable core wire
to remove end play. Measure and record the distance between
mark and end of casing.
• The distance between forward and neutral must be no less
than 1-1/4 in. (31,8 mm) and no greater than 1-3/8 in.
• The distance between neutral and reverse must be no less
than 1-1/4 in. (31,8 mm) and no greater than 1-3/8 in.
Note! Check your remote control installation instructions, if
your measurements are not within these specifications.
Make sure the cables are attached correctly inside the
control box before continuing. All control boxes must
meet these minimum and maximum specifications in
order for the shift system to function properly.
At the back of the drive, disconnect the shift cable from the linkage and try to push and pull the cable in and out. Should be less then 1/4" of play.
Next is to follow Volvo's procedure to check for the correct amount of stroke.
- Move remote control handle to the wide-open-throttle position in forward gear to retract the shift cable. Pull out cable core wire to remove end play. Mark cable core wire at end of casing.
Measure and record the distance between mark and end of
casing.
3. Mark cable core wire at end of casing with control in the neutral
detent position.
4. Move the remote control handle to the wide-open-throttle position
in reverse gear to extend the shift cable. Push in on cable core wire
to remove end play. Measure and record the distance between
mark and end of casing.
• The distance between forward and neutral must be no less
than 1-1/4 in. (31,8 mm) and no greater than 1-3/8 in.
• The distance between neutral and reverse must be no less
than 1-1/4 in. (31,8 mm) and no greater than 1-3/8 in.
Note! Check your remote control installation instructions, if
your measurements are not within these specifications.
Make sure the cables are attached correctly inside the
control box before continuing. All control boxes must
meet these minimum and maximum specifications in
order for the shift system to function properly.