Do you know if you could possibly have defective bolts do you know manufacturer date of your lsd
What bolts are you speaking of? Wheel? Or differential?
All m3 bushings, diff was installed with brand new BMW bolts as per manual.
Installed new guibo and inspected center bearing support and universal joint and driveshaft to diff collar nut...all tight, normal play. When riding in the back...the helicopter sound did not seem to emit from center of back seat where the differential is located. I sounds like it is coming from left wheel. Only when coasting, or braking, or neutral does the helicopter come into play.
Transmission shifts flawlessly, fast, no issues when applying power...no matter how much. The only thing that is a problem is the helicopter sound when letting go of the gas pedal.
So I think that the wheel bearings need to be replaced...although I replaced them a little over three years ago. But...I have been working at an address with lots of pot holes and been on those roads for almost two years daily. Like...SHITTY potholes and rough surface with RR tracks too... for about 1.5 miles every day. Jarring surface... not acceptable for driving over 30 mph safely. And I did replace shocks with Koni Yellows on medium setting in front and firm setting in rear. Maybe this combination of things is the perfect storm for accelerated decrepitude of the rear wheel bearings.
Anywho, I am going to replace the stock brakes with M sport rear brakes and new rotors and steel lines this week. So new brakes, new rotors, new wheel bearings... and if it still sounds like a helicopter...well, then I guess I have to get a new differential. Damn... This time, I will try wavetrac instead of M Factory.