Trailblazer 2007 transmission
My Chevy 07 blazer won’t shift from second gear to
higher unless you hit the gas to 120km/h and
decelerate that rpm hits 1 and shifts to 3rd. At
times it shifts without having to fly on 5000rpm. It
started after I changed the transmission oil a year
ago. The mechanic had drained the filter too. When
I inquired the other guys told me that you never
ever should drain off the transmission oil. Now,
what do I do?