I'm running a dana 35. Since I fitted it I immediatly became aware of a knocking noise at the rear. I replaced the shackles, shock bushes, removed the leaf springs, greased everything up back there, eventually I found out that it was the axle. It appears the dana 35 is designed to have about 1/8 in end play allowing the half shafts to move in and out. The truetrac for some reason is allowing a little more than this 1/8 in and the noise is the hub knocking against the end of the axle when you rock the wheel/tyre in a sideways motion. A slightly modified thicker or stepped C clip would reduce this excess movement, but it's not essential as no harm will be done. I'm also thinking about welding a thin ring on the end of the axle say 2mm think, to lengthen the axle tube. The movement is only excessive on one side (left side). I read elseware on naxja that the D35C axle's were finnished off by DC and not to the highest standards, ie axle tubes going in off centre etc. I realise every Jeep is different and I'm figuring I may well have a D35C with an axle tube pressed in say 1mm more thus allowing more movement.