Had one of those Detroit true Trac, it was gear driven. Here the story on. My son order it through his work,he gave them all the info and vin#. They sent wrong one, so they sent correct one. The mechanic took my old one apart and was putting the new together, The bolts shoulder was to big. It lacked about 1/4" getting tight, called up 4 wheel parts and they uh . We got a install kit for another 110.00 it might work told them no thanks. They sent the return labels then sent the first one back so got another return label sent it back. Finally disputed the charge on Friday. I thought 4 wheel parts was better than that. Going to leave 10/5 head down to Durango and get this Dana Trax loc installed