for customer W123 300D.

The skronking rattle crunch sounds you described on the phone should be:
The rear sway bar link plastic ball socket is seriously corroded.

You have two ($1,300.00) new OE axles, and verified the boots are perfect (no leaks).

The oil leaking from the center of the trailing arms + rear body roll + bouncing rear end = bad shocks.

The rear shocks are generally an easy diy.
PeachPartsWiki: Replacing the Rear Shocks & Springs


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__________________
ASE Master Mechanic
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Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
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1985 300SD
1983 300D
2003 Volvo V70

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