I looked this up and came up with a bunch ranging from $ 200 to $ 30 Early R129 SL , Early W202 C class and W124 E look to be the same. Just be sure if you have 4 channel ABS that there is a place for the wheel speed sensor.

1987 Mercedes 300D (includes CD/D/SD/TD)

Rear Knuckle/Stub Axle

124 Type, 300TD, RH