Originally posted by rickjordan
From what I have read, if your rear wheels appear to be "squating", this is caused by the rear suspension bushings being worn out.
a better indicator of worn suspension bushings is the feeling that the rear end of the car is steering itself. particularly during squat or dive.
the true test is to jack the car up and attempt to move the rear wheel relative to the body of the car. if the wheel moves in any direction that is not consistent with normal wheel travel during suspension compression and extension you have worn rear suspension bushings.
the crux of the 5-link rear suspension ability to provide zero rear-end steering is the operation of the bushings.
consider that the rear half shaft is of a fixed length and fixed at one end. simple geometry dictates that as the free end moves in its track it must also move in an arc. various systems have been designed to deal with this problem. MB's system has come the closest to eliminating it. the deflection has been reduced to 1/64th of an inch.
the bushings are an active part of the suspension design and the required hardness of each bushing has been calculated. MB did not just throw in any old rubber for the bushings. as such, the bushings are under a considerable amount of strain and WILL wear faster than what most people would consider normal. particularly if the car is driven hard.
the inrtoduction of rigid suspension arms (the custom camber arm that have been sold on bnzsport and 190revolution) look trick, but they could very well transfer the forces that are normally absorbed by the bushing to the mounting points. this could manifest itself as metal fatigue around the mounting points in the future.