There are several possibilities;
The transmission pump or leaking internal seal or o-ring
Shifter adjustment to assure each indicated gear puts the gear switch into the proper detent/position.
The gear shift safety lockout between the brake pedal and the shifter switches may have failed or need adjustment.
I am attaching several diagrams and tests to help with the diagnostics.
As far as the suspension goes, I cannot see any suspension isssues that would keep a transmission from shifting. It would have to be a major damage or defect issue. It could also possibly be the axle on the transmission side.
The first thing I would suggest is to go to an Advance Auto or an Auto Zone and have them run the trouble codes. They will generally do this for free.
Come back to use when you get the codes.
Sunday, August 20th, 2017 AT 6:39 PM
(Merged)