W124 sedan rear shock procedure

[anthonyb]

Hi everyone,

Did the rear shocks on my 300E a couple of weeks ago. Despite reading the shop procedure and the many posts on this site, it still took me about 3 hours to figure out how to do the first shock. After figuring it out, it took about 30 minutes to do the second, so I thought I'd write up how I did it in case it could save anyone some time in the future. (Note that this required two people in my case, but if you are beefier than I am you could probably do this by yourself)

Tools:

Floor jack + jackstand (1)
breaker bar + 17mm socket
17mm open end/box end combo wrench
1/4" ratchet and 10mm socket
medium/heavy gauge wire

1. Yank out the trunk liner panels. For the side panels, I found it easiest to start by pulling on the far (cabin) side first and bending them back.

2. Upper shock mount: using the 17mm open end wrench on the lower nut as a counter-hold (I used my foot for leverage on this one), loosen and remove the upper locknut with the breaker bar. Remove the bottom nut, pull off the washer and bushing.

3. Jack up the relevant corner of the car, then lower onto a jackstand so the tire is just resting on ground. Although you shouldn't have to worry about a spring coming loose (!), I thought it would be best to have it in contact with the ground just so it wouldn't stress the sway bar link too much.

4. Remove the 10mm nuts securing the wheel carrier cover, then unbolt the 17mm bolts for the lower shock mount.

5. With one person pushing on the top of the piston rod, pull down on the shock body from inside the wheel well. (I needed two because mine were still pretty firm, though worn.) Pull the top into the wheel well, then pull it up to unseat the bottom and remove.

6. Insert the appropriate rubber bushing (one of two in the kit) on top of the shock.

7. If your shocks are precompressed, skip to the next step. If not, have your partner compress the shock, while you wire both ends together to keep it compressed. (Obviously, don't wire it through the bolt holes.)

8. Insert the bottom of the shock into the lower mount, making sure the bolt holes line up, insert the lower bolt (this is important to do FIRST!) then slowly undo the wire and let the top rise into the upper mount.

9. Start the lower nuts, but don't fully tighten them.

10. Insert the other rubber bushing on the top mount, inside the trunk. Add the washer, then the first nut (15-18 Nm). Counterholding the bottom nut, install the lock nut (30 Nm).

11. Lower the car off the jackstands and drive it forward and back a few feet to settle the car.

12. Tighten the lower bolt to 55 Nm, and reinstall the wheel carrier cover.

Hope this helps, and let me know if there's something I need to add!

Anthony