Reply to "side shaft play"

It really depends upon how sinister that noise is. When I hear a noise, I usually go looking for it too. It's rare that they fix themselves.

IMO, slight play in the drive flange isn't necessarily an indication of a problem. It's just a floating spline and is no indication of whether the carrier is shimmed at proper clearance. Quella has done a lot of ZFs, and though possible, I doubt he would make an error during a simple flip.

The ZF is a limited slip differential trans and of course when you turn, the inside wheel must slip because it travels a shorter distance than the outside wheel. This slip must occur either between the tire and the ground or in the clutch mechanism of the differential.

Years ago, I had buddy that was a drag racer set up the rear end in my mid-year vette for me. It drove fine cold but when it got heated up a bit, it would make a hell of a clunking noise while manuevering in parking lots. It sounded terrible and like it was coming from out near the rear wheel. Turns out, it was dragging the inside tire during low speed turns, stretching all the rubber bushings in the suspension joints to the max, and then the joints would catch up and let loose and make a hell of a clunk, some times several in succession. I chased it for a while thinking it was a bad u-joint. Being a drag racer, my bud was inclined to set up limited slip dif's a little too tight. I finally pulled the rear end and set up the clutch packs a little less aggressively and problem solved.

You mentioned your ZF is new. You likely have heim joints in your 40's suspension not rubber bushings. Maybe it's just got a tight differential pack and the heim joints do a good job amplifying the noise as it slips when you push your car?

Good luck.
Kelly