I know this has been discussed. I'm talking about towing our 5ver up a steep grade with stops for road work. When taking off from a dead stop, and when the trans shifts to second or 3rd gear with rpms under 1400 the trucK SHUDDERS. SNOKING WAS TALKING ABOUT DRIVE shaft angles. However, the owners Manuel discusses "TORQUE CONVERTOR SLIPPAGE". Transmission temp went from 165 to 178....I'm thinking the tow rating of 16660 is overly optimistic with a numerically low 3:42 rear axle... I don't think this happens with a 4:10 axle. Anybody with 4:10s have this shudder?. Thanks.. I know smoking mentioned drive shaft, however, I'm concerned about torque converter.