Hi, I have a 74 corvette and I am getting a strange limited slip chattering coming from the driver’s side. What is strange is I don’t get the noise when turning corners. If I go to a parking lot and do figure eights and full donuts at slow speeds no noise and all is good. Clutches seem to slip without issues. Problem is AFTER the diff is warmed up, if I stop a light or similar hold the brake and give throttle, i.e. brake stand, then the driver’s side diff starts to chatter. Car is not moving, tires are not turning, just applying steady throttle, engine RPM steady at 2100 ish. What is also strange is rolling forward light throttle no noise, but rolling in reverse light throttle causes chattering (backing up into the garage). This only seems to happen once the diff gets warm. Using an infrared temp gauge the diff is usually at around 120F max after a 20 min rip on the freeway which seems ok to me. A little background. I have replaced both rear spindles, bearing and seals. Close to .002 endplay when spindles installed. Checking the wheels doing the hands at the 10 and 4 o’clock positions practically no movement is felt. Temp readings on wheel bearings show slightly higher (10-20F) then ambient, no noise etc. so I am pretty sure the wheel bearings are good. Also when I changed the spindles, all half shaft u joints got replaced. No movement or binding in the u joints that I can see/feel. Wheel cambers set as close to stock as I could. Any thoughts or ideas would be appreciated. I did change the oil out as much as I could using a fluid hand pump and replaced with royal purple 75W-90 gear oil. Before I go and start adding extra additives I figured I would see if anyone with more experience then me has any ideas what is going on. This doesn’t seem to me to be a standard chatter issue simply fixed with additives.