I've read that the valve body is weak on the CD4E automatic in the contours. Mine has been fine so far, so I don't have any direct experience. The shifting is controlled via computer and the neutral position switch may be a cause, but I can't verify this off the top of my head. There is a group buy on a valve body kit which may help out. Resetting the computer fixed some rough shifting on mine, so may be worth a try.
