I read a number of postings on this group and others about my ABS warning light and my auto trannie not shifting out of first. I felt it worth it to take the gamble and replace the differential speed sensor that I got at Kragen for $11.99. Voila, everything straightened out in that one fell swoop. Thank goodness for those of you that went before me and shared info that saved me tons of time and trouble and bucks getting my truck back on the road.