I have an 88 (old body style) 3500 with a 6.2, banks turbo and a nv4500 tranny,4x4.Right after I put the 5 speed in the front balancer went bad, the key and the key way on the balancer broke. I got another one it fit on the crank tight, so I thought I was good to go. Five thousand mile late this balancer is bad. Same thing. the key is wittled down to nothing and the balancer key groove is wollered out.Whats up ?? is is somthing to witht the five speed ( the rev up and deceleration of the engine to shift ?) Also just a note,I have a 88 full size blazer 3/4 ton 350fi/350 tranny 35 inche tires and 3.73 gears, I think it pulled the trailer and the S-Ton just as good as the crewcab deseil pulling truck !!!! any help with the crank problem would be apprecieated.