Replacement: rear lower arm – Mercedes W204. Tip from AUTODOC:
The replacement procedure is identical for the left and right lower control arms.
Please note: all work on the car – Mercedes W204 – should be done with the engine switched off.
Carry out replacement in the following order:
Step 1
Secure the wheels with chocks.
Step 2
Loosen the wheel mounting bolts. Use wheel impact socket #17.
Step 3
Raise the car.
Replacement: rear lower arm – Mercedes W204. AUTODOC experts recommend:
If you are using a jack, make sure it rests on a flat surface without any unevenness.Be sure to additionally secure the car with jack stands.
Step 4
Unscrew the wheel bolts.
AUTODOC recommends:
Warning! To avoid injury, hold the wheel while unscrewing the fastening bolts. Mercedes W204
Step 5
Remove the wheel.
Step 6
Unclip the fasteners and remove the suspension arm plastic cover. Use a flat screwdriver.
Step 7
Unscrew the fasteners of the underbody plastic cover. Use a drive socket #10. Use a ratchet wrench.
Step 8
Clean all joints of the arm. Use a wire brush. Use WD-40 spray.
Step 9
Unscrew the fastener that connects the suspension arm to the stub axle. Use a combination spanner #18. Use XZN #12. Use a ratchet wrench.
Step 10
Remove the fastening bolt.
Step 11
Clean the subframe bracket fasteners. Use a wire brush. Use WD-40 spray.
Step 12
Support the subframe. Use a hydraulic transmission jack.
Step 13
Unscrew the subframe bracket fasteners. This is necessary to access the upper fastening bolt of the suspension arm. Use Torx E10. Use Torx E14. Use a ratchet wrench.
Step 14
Remove the fastening bolts.
Step 15
Remove the subframe bracket.
Step 16
Unscrew the fastener connecting the control arm to the subframe. Use a combination spanner #18. Use XZN #12. Use a ratchet wrench.
Step 17
Remove the fastening bolt.
Step 18
Remove the arm.
Step 19
Clean the suspension arm mounting seats. Use a wire brush. Use WD-40 spray.
Step 20
Clean the subframe bracket mounting seats. Use a wire brush. Use WD-40 spray.
Step 21
Install a new arm.
Replacement: rear lower arm – Mercedes W204. Professionals recommend:
During the installation process, use only new bolts and nuts.
Step 22
Install the fastening bolts.
Step 23
Install the subframe bracket.
Step 24
Install the fastening bolts.
Step 25
Tighten the subframe bracket fasteners. Use Torx E10. Use a torque wrench. Tighten it to 28 Nm torque.
Step 26
Tighten the subframe bracket fasteners. Use Torx E14. Use a torque wrench. Tighten it to 80 Nm torque.+90°
Step 27
Remove the support from under the subframe.
AUTODOC recommends:
Replacement: rear lower arm – Mercedes W204. Tip:
Step 28
Support the rear knuckle. Use a hydraulic transmission jack.
AUTODOC recommends:
For tightening the fasteners correctly, you have to jack up the suspension components to their working position.
Step 29
Tighten the fastener that connects the suspension arm to the stub axle. Use a combination spanner #18. Use XZN #12. Use a torque wrench. Tighten it to 50 Nm torque.+90°
Step 30
Tighten the fastener connecting the control arm to the subframe. Use a drive socket #18. Use XZN #12. Use a torque wrench. Tighten it to 50 Nm torque.+90°
Step 31
Remove the support from under the rear knuckle.
AUTODOC recommends:
Mercedes W204 – Do not lower the transmission jack sharply to avoid damaging components and mechanisms of the car.
Step 32
Treat the subframe bracket fasteners. Use copper grease.
Step 33
Treat all joints of the arm. Use copper grease.
Step 34
Screw in the fasteners of the underbody plastic cover. Use a drive socket #10. Use a ratchet wrench.
Step 35
Install the suspension arm plastic cover.
Step 36
Clean the wheel rim mounting seat. Use a wire brush.
Step 37
Treat the surface where the brake disc contacts the wheel rim. Use ceramic grease.
Step 38
Clean the brake disk surface. Use a brake cleaner.
AUTODOC recommends:
Replacement: rear lower arm – Mercedes W204. After applying the spray, wait a few minutes.
Step 39
Install the wheel.
AUTODOC recommends:
Warning! To avoid injury, hold the wheel while screwing in the fastening bolts on the car. Mercedes W204
Step 40
Screw in the wheel bolts. Use wheel impact socket #17.
Step 41
Lower the car and working in a cross order, tighten the wheel bolts. Use wheel impact socket #17. Use a torque wrench. Tighten it to 130 Nm torque.
Step 42
Remove the jacks and chocks.
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