If you have a bad torque converter will that turn the fluid dark and smell a little burnt? Have a 99 2500, tranny was rebuilt @ 40,000 miles ago, fluids changed and bands adjusted, but getting the shudder when towing @35-40 and 50-60 MPH. Drive shaft U-joints to be replaced soon. AAMCO said fluid looks great so can't be the converter. Any suggestions appreciated.