Rear wheel bearing/axle shaft size mismatch

Sure. For ease of production or a rare engineering goof, the Pantera rear axle is undersized by about 0.0005" (a half-thousandth). This means that the ID of the rear bearings and the OD of the axle shaft are essentially identical- and the axle is low-carbon steel while the bearing race is ultra-hard steel. Ball bearings require an interference fit on a shaft to work as designed. This all results in a SLIGHTLY loose fit when everything is up to temperature. With 300+ ft-lbs of torque going thru the rear axles, the axle moves a little inside the bearing- and being softer than the bearing, it gradually get pounded into a small diameter, causing a rear wheel wobble. So unfamiliar mechanics, seeing the wobble, will replace the bearings when 98% of the time it's the axle thats shot. Any removed rear axle should be checked for diameter with a 5-place micrometer- most will be about 1.5740" (and will be smaller in the discolored areas under the bearings) while they need to be 1.5745-1.5750". Lengthwise scratches from pressing are of minor concern. Vendors long ago realized this, and offer aftermarket axles made of 4130-or similar high-strength steels, made in the required oversize for a proper press fit. If you wish to test your Pantera, with the rear tub out, have someone throw a haunch into your rear fender while you watch the inner end of the halfshaft. If the axle or bearings are bad, the halfshaft end will move upward as the car deflects a bit. The more it moves, the worse the wear- I've seen a track in axles as wide as the bearing race and 1/4" deep.... and these are hollow axles! High-horsepower track-racers can snap the axle flanges off new stock axles with gumball tires, so they always go to the high-strength aftermarket axles for sheer safety. For street cars, stock axles can be carefully welded and reground to oversize, if you know what you're doing. Multiple in-detail articles have been written since about 1975 on this subject in P.I and POCA newsletters.