[Jim B]

On the checklist don't overlook possible tire rub (I would think tire slippage on the rim has been eliminated) on the leave or a broken/partially stripped heim socket or end/weld or chassis/housing attaching bracket that may not look broken but actually is. Also double check the posi/spool/axle spline condition paying close attention to the side that the car pulls to on the leave. Keep in mind I've seen failures that only produced a symptom in the lower gears at first (gear multiplication factor) until the failure got worse. Then the symptom occurred in the higher gears. Of course, you want to find the problem before it gets to total failure and is becomes obvious at that point.