300e differential clicking

[BDBENZ]

I have a loud clicking noise from the left side rear axle or differential when I hold at a steady below 30 mph speed, worse when I decelerate or turn right. Does not do this when I turn left. I have checked the parking brake, and rear wheel bearing and both appear to be tight or in order. Stock wheels. When car is on the jack, noise is not appearent. I also checked the flex disk and it is good. Boots are good on axles, any ideas?