Stray Benzes: How to Replace Lower Ball Joints on Classic Mercedes (W126, W123)

Working on the lower ball joint can be quite a beast of a job. Basic ball joint tools may not work without modifying it. Here is a video about one such job where the ball joint was quite stuck. The ABS sensor was stuck also and needed to be left in place. Video Chapters [00:01] Introduction: Why this job is one of the most difficult and a major safety concern. [01:13] Disassembly Strategy: Steering linkage and ABS sensor considerations. [02:34] Removing the Brake Caliper: Detaching M12 bolts and securing the caliper. [04:41] Dust Cap and Hub Removal: Accessing the spindle and bearing. [09:36] Getting to the Ball Joint: Removing the dust shield and identifying wear. [11:56] Stabilizing the Assembly: Using the shock absorber to keep the spring seated. [14:13] The Main Challenge: Modifying rental tools for the unique Mercedes axle shape. [17:11] Pressing the New Ball Joint: Grease, concentric alignment, and force. [18:20] Protecting the Boot: Removing the rubber boot during installation. [19:12] Reinstalling the Boot: Using specialized tools to seat the spring wire. [21:41] Reassembly: Tightening the lower and upper ball joints. [26:51] Final Steps: Mounting the wheel hub, shield, and adjusting bearings. [30:16] Safety Protocol: Pumping the brakes before the test drive. Video Summary Ralf details a grueling process that involves more than just a simple part swap—it’s a battle of mechanics and custom-modified tools [14:13]. This video is a vital resource for anyone attempting to refurbish their classic Mercedes front suspension. Key Technical Highlights: Safety First: Ralf starts with a strong disclaimer that suspension work is safety-critical [00:23]. He notes that the shock absorber plays a key role during the process by preventing the coil spring from unexpectedly flying out of its seat [11:56]. Rental Tool Limitations: Standard ball joint press kits from auto parts stores often require significant modification to work on the W126. Ralf explains how he had to cut and modify a press sleeve to clear the "funky shape" of the steering knuckle so the force remains concentric [16:26]. The "Bust" Factor: To remove the original ball joint, Ralf had to cut off the top of the old joint to create room for the press tools [15:46]. He emphasizes that the job requires a heavy amount of grease on the press rod to prevent it from seizing under the extreme force required [16:56]. Boot Preservation: A critical tip is to remove the new ball joint's rubber boot before pressing it in. This prevents the boot from being crushed or manhandled during the high-pressure installation [18:20]. Ralf then uses a body tool to carefully reseat the boot and its spring wire afterward [19:12]. Brake Protocol: As with all brake-related work, Ralf concludes by reminding viewers to pump the brake pedal multiple times before driving to ensure the pads are properly seated against the rotors [30:16]. Video URL:    • Stray Benzes: How to Replace Lower Ball Jo...