From no issues to this: Can drive in first gear. As soon as tranny upshifts to 2nd— loud screeching. Put it in reverse, and basically no movement and a lot of screeching. Can coast in neutral, drive in third. Is my transmission shot, and if so, what is the cheapest way to get it back ion operation? I.E. Used, rebuilds, etc. BTW, truck only has 115K miles. Changed transmission fluid and filter at 90K.