MB Medic Mercedes-Benz Repair Guides, Service, How To DIY
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In this guide (5 sections)
Replacing the front shock absorbers is one of the easiest tasks you can tackle on your ML. These instructions apply to the Mercedes-Benz W163 M-Class built from 1998 to 2005: the ML320, ML350, ML430, ML500 and ML55 AMG. Below you will find step-by-step instructions, a video at the end of the article, related part numbers, plus torque specifications. The shocks are relatively inexpensive and will dramatically improve ride quality. No more bouncing all over the place or floating like a boat on the highway. Shocks wear at a similar rate on both sides, so do them as an axle pair. If the rear end floats too, that is a separate job at the back of the car, where the W163 uses a combined spring and shock assembly rather than the plain damper you are replacing here.
Applicable Part Numbers
- 163 326 11 00, 163 326 1100, 1633261100
- Chassis (years) Model note 163.154 (1998 to 2003) ML320 from ch# A 145273
- 163.154 (1998 to 2003) ML320 from chassis X 707756
- 163.157 (2003 to 2005) ML350
- 163.172 (1999 to 2001) ML430 from chassis A 145273
- 163.172 (1999 to 2001) ML430 from chassis X 707756
- 163.174 (1999 to 2001) ML55 amg
- 163.175 (2002 to 2005) ML500
- 163 326 12 00, 163 326 1200, 1633261200
- 163.154: 1998 to 2003: ML320: through chassis A 145272
- 163.154: 1998 to 2003: ML320: through chassis X 707756
- 163.172: 1999 to 2001: ML430: through chassis A 145272
- 163.172: 1999 to 2001: ML430: through chassis X 707756
Step-by-step instructions on how to replace the front shock absorber on a 1998 to 2005 ML W163.
- Park on level, stable ground and chock the rear wheels, since those are the wheels still carrying the car once the front is up. Loosen the wheel bolts, raise the front at the lifting points Mercedes-Benz designates for the W163, and lower it onto appropriately rated jack stands before going near it. Never work under a vehicle held up by the jack alone. Then take the wheel off.
- Remove the fender liner. You can also access the upper shock nut from the engine compartment. On the passenger side, remove the air filter housing for access
- One thing to get right before you start: the shock itself comes off with the car raised and the wheel out of the way, but the LOWER bolt must not be finally tightened until the vehicle is back on its wheels at normal ride height. Torquing that bolt with the suspension hanging preloads the bush and shortens its life. The last step below covers it. Once you remove the intake air housing, you will see the nut, as shown below.
- Remove the nut at the top. You will need to counterhold the shaft of the shock.
- Remove the bolt that holds the shock absorber to the lower transverse control arm. If that bush is cracked or the arm moves at its mountings, deal with it while everything is apart: the front sway bar and torsion bar bushings are a related job on the same corner.
- Remove the old shock and fit the new one, upper mount first, then the lower bolt started by hand. Fit a NEW self-locking nut at the top rather than reusing the old one: a prevailing torque nut is designed to be used once and it is the only thing holding the top of the shock to the body.
- Refit whatever you took off for access. On the passenger side that means the air filter housing, and on both sides the fender liner. Put the wheel back on and lower the vehicle to the ground.
- With the vehicle resting on its wheels at normal ride height, now tighten the lower shock absorber bolt to its torque figure. This is the step that cannot be done in the air. Note: The passenger side upper mount is easier to access after removing the air filter housing. The driver’s side can be replaced by accessing it from the engine bay without removing the wheel fender liner. There is less space to access the nut at the top of the shock for the driver’s side, but it can be done. Remember that the lower bolt gets its final torque only once the vehicle is back on its wheels.
Video: Mercedes-Benz W163 M-Class Front Shock Absorber Replacement
Torque Specifications
- Bolt connecting front shock absorber to the lower control arm: 130 Nm
- Self-locking nut at the top of the shock absorber, where it connects to the body: 30 Nm
Instructions apply to:
These shock absorbers fit the W163 M-Class as follows.
- ML320: 1998, 1999, 2000, 2001, 2002 and 2003
- ML350: 2003, 2004 and 2005
- ML430: 1999, 2000 and 2001
- ML500: 2002, 2003, 2004 and 2005
- ML55 AMG: 2000, 2001, 2002 and 2003
Before you buy parts, scan every control module, not just the engine. It shows the root fault behind the warning lights and tells you whether the problem is still active. See how to do a full health check.
Tip from a technician on this job:
1. Turn the steering wheel outward to get easier access to the 22 mm lower bolt.
2. With the car on the ground the suspension is compressed. The old shock has to be compressed by hand to come out, and the new gas charged shock is longer than the space between the mounts. Working from below also risks scratching the chrome rod, which damages the seals.
An easier hybrid method:
a) Raise the side you are working on and support it on a jack stand.
b) Remove the wheel so you have room to reach the 22 mm bolt.
c) Remove the upper rod nut from the engine compartment.
d) Slide in the new shock and secure the upper nut.
e) Fit the 22 mm bolt through the shock bushing and the lower control arm, hand tight only.
f) Reinstall the wheel.
g) Lower the car to the ground.
h) With the weight of the car on the suspension, torque the 22 mm bolt to 130 Nm.