First off shock shift 1-2, can be caused by either a bad dropping resistor allowing TOO MUCH voltage to shift solenoids or a broken 1-2 accumilator shift valve spring{valve body}.Second shifting in and out of gears highway.Common problem on J30's.What happens when starting from a stop is: shift: 1-2,2-3,3-overdrive,overdrive-torque convertor lock-up{engine and trans input at same rpm's}As long as you are cruising with accelerator on it will remain in tcc lockup.As soon as you release accelerator trans downshifts to overdrive.When you again accelerate, given the right speed it goes back into lockup.Try it on the highway.Get up to cruising speed then release throttle then right away return throttle.You will feel a bump when tcc disengages/engages.This is not severe and the fix is to replace the valve body.Very expensive.Metal in the pan?That is another story.