Every since I bought the 98. 5 TD 2500 I would have erratic shifting between 45 - 50 mph. Even after going to the dealer and having the program flashed no luck. On long trips with the GPS and Sat. radio going the erratic shifting would start. Before this last trip I looked in the books to see what battery was used on the 99 and up models. I purchased the larger batteries and clamps and after 9278 miles no problems to report. I read in past issues of people trying all sorts of remedies to fix this problem. I suggest that everyone look at the batteries before doing anything else.