Ol'Yeller, I just finished my overdrive switch/shifter lever replacement using your excellently written instructions. Before trying this seemingly intimidating task I was ready to hand it to a dealer. Thanks for pioneering this repair and posting it. It should probably be in the most common questions reference if it's not already. I can see where this will be one of the most common repairs needed on the older Super Dutys due to original design problem of short wiring.

After the swap out, I opened the wiring on the old shift lever, after ohming out the ends which showed opens on two wires. Sure enough, the two little wires were broken right where the cable passed through a strain-relief point. This was adding strain instead of helping to relieve it due to the short length of the original cable. I would also recommend checking the button switch with an ohmmeter before replacing it, its probably not the problem.

Either way, the new shift lever has a much longer cable and hopefully will last longer.

Thanks again.