Today I was towing my 4 wheeler when my Suburban refused to shift. It was at 4000 RPMS when it finally did. This happened while turning a corner and accelerating. The RPMS would then rev up to 4000 rpms when braking. Also while going 60mph the truck would cruze along at 2000RPMs but when doing 70mph the truck would be at 1800 RPMs. This was all in tow/haul mode.
The vehicle is a 2011 Suburban 2500 with 28000 miles. Anyone have any ideas. I will have the dealership look at it on Wed when the truck goes in to have some rust fixed on the inside door jams of both driver and passenger side doors.