Classic/Antique Car Repair: 67 GTO Convertible rear end noise, axle bearings, torque wrench

Question
I moved, drove the car 180 miles with no problem. It sat for a month and now a metal to metal noise comes from the rear. You can't really feel it like if the rear end gear was shot and the tranny seems to be fine. It seems more prevelent drifting in gear or in neutral. I'm starting with the U-joints. What else could it be?

Answer
It could be u-joints, but usually they make noise mostly at low speeds with a load on them (pulling or backing up) and they usually shake your teeth out with vibration when they are about to let go.  Since this can be so dangerous, particularly if the front on comes apart, I think you are wise to check them anyway.  The noise, however is more likely coming from the rear end.   The culprits are the pinion bearing (when you have the driveshaft down, grab the companion flange; it is the part the u-joint bolts to and see if there is any slop there).  If there is, or if the noise changes between pulling and coasting, it is probably the pinion bearing, even if you don't feel any monkey motion in it.

Also, try to determine whether or not the noise is dependent on whether or not you are in a turn.  If it gets louder on a right turn, it is the driver's side axle bearing, or vice-versa.   The axle bearings are fairly easy to change - the pinion bearing requires some knowledge and a very big torque wrench - probably best left to a pro.

Dick