Mercedes-Benz W124 coil spring and shock absorber replacement
How do you replace the W124 rear springs – is a spring compressor needed?
A compressor is not needed for the rear springs. Lift the car, remove the wheel, place a trolley jack under the lower control arm, remove the bolts at the lower end of the shock absorber and lower the control arm in a controlled way. Take care that the jack does not slip out; the spring is removed only once the control arm is down. Support the car on stands and never work under it on a jack alone.
How do you replace the W124 front springs?
The front springs require a proper spring compressor, because an unsuitable compressor can let the spring fly out and cause serious injuries. Check the cups at the upper end of the spring and replace them if needed. Spring work is safety-critical, so if you do not have compressors, have a workshop do it.
What causes rattling or a stiff rear end after replacing the springs or shock absorbers?
The cups at the lower end of the spring can be full of rust, so the spring does not seat properly: clean them before installation. A worn rear shock absorber does not limit the spring's travel, and the control arm bangs in potholes. A cracked rear spring often stays hidden in the lower cup; if one is broken, replace both.
What do the colour markings on the W124 rear spring mean?
A blue dot means a long spring and a red dot a short one. The colours in the middle of the spring are production markings and do not tell the length. The part number is stamped at the end of the spring coil.