I started towing a 5th wheel camper and experience a jerking in the truck in any gear above 3rd gear and between 2200 rpm and a little above 3000 rpm. If I manually down shift causing rpm to be above 3200 rpm and above it will stop jerking. I took truck to dealer with camper attached and duplicated jerking in the above mentioned rpm range, he had computer connected to truck and when he unlocked converter jerking stopped. He locked converter and jerking started again within the 2200-3000 range. GM and he does not think it is a converter is the problem still waiting for them to contact me. Has anyone had a similar problem and what was the resolve?