2006 Silverado 1500 4l65e Transmission

I sent my truck to have all brake line's changed and
decided to have transmission serviced. I had drove
it for about a week and was getting on the
interstate when it jumped out of drive. After I had it
pulled over I figured out I had manual 1st and
second , so I headed home. When I have it in first it
drive normal . when I shift into second it makes a
scrubbing noise until I get to about 25 mph then
the scrubbing stop's. After I get to about 40 I could
shift into 3rd and it run normal until I got down to
40 mph and then it jumped out of gear . I had no
4th (drive) gear . after I got it home it looked like
the transmission fluid had got hot and started to
get darker . I have no check engine light or no abs
light on. I checked the codes and I had two radio
codes because door speakers don't work and I
have all three wheel speed sensor codes . I have
changed the rear wheel speed sensor and one of
the front bearings and speed sensors are almost
new . I have looked at the wiring to sensors and
can't find nothing wrong . what's happening to my
transmission ?