E36 BMW M3 Rear Strut and/or Strut Mount Replacement

Adam & Larry, 13 December 2003

I'd like to thank my friend Larry Barbieri who donated his time and garage to help me with this procedure one brisk morning this past December.

This write-up outlines the procedure to replace your rear struts and strut-mounts. When Larry and I did this, we did not actually replace the rear struts (as mine were not worn out) but replacing the rear strut mounts requires removal of the rear struts so replacement is simply a matter of swapping in new ones for the old before reinstalling.

The rear strut mounts secure the rear struts to the body of the car and contain a hard rubber bushing which wears out over time. Take a look at fig. 1, below. The rubber bushing is the part of the mount that looks like a Duncan Butterfly yo-yo. Notice that in the old bushing the top half of that yo-yo has worn down so that the two sides are no longer symmetrical. Furthermore, there is a metal insert in the center of the rubber bushing that, in my car, had broken completely free of the rubber and was causing a harsh "something's-scraping-on-the-body" sound whenever I went over a bump. Luckily, the rear strut mounts are easy to replace.

Step 1: Remove Trunk Lining & Loosen Strut Mount Nuts

In order to access the rear strut mounts, the trunk lining needs to be pulled away from the body of the car. Remove the floor carpeting (which covers the spare) and then remove the two plastic fairings from either side of the spare. On my car these were held in place with a combination of 10mm plastic nuts and press-fit hardware (which are simply pulled off). I'm not sure why the hardware was not consistent - I suspect some of the original press-fit pieces got lost somewhere along the way.

Next, remove the tail light covers (twist lever and pull away) and the storage tray on the passenger side of the car (which actually conceals the battery) which simply lifts out. Finally, pull the carpeting away from the body to reveal the rear strut mounts. See figs. 2-4.

On Larry's car (which is a 1995) he had to drop the rear speakers in order to access the strut mounts, although I did not have to. Also on my car (1996 model), there was a protective plastic cover on the trunk-side of the wheel well which was missing from the 1995 model.

Step 2: Loosen Lugs & Jack Car

Loosen the lug nuts (17mm) while the car is still on the ground. Jacking the car with a hydraulic pump is a no-brainer and we were able to easily support one corner of the car at a time, using a single 3-ton jack stand. Adjust the stand to be just high enough to get the rear wheel off the ground. If you do not have a hydraulic jack review my proper jacking procedure and apply a similar methodology to the rear of the car. I highly recommend doing one corner at a time either way.

Remove the wheel.

Step 3: Support Rear Trailing Arm Assembly & Remove Lower Strut Bolt

Use your jack to support the rear trailing arm assembly. Remove the lower strut bolt with an 18mm socket. It helps to hit this bolt with penetrating oil prior to removal.

Step 4: Remove Rear Struts

Working with a friend, have one person hold the strut from below while the other person removes the two 13mm locking nuts which hold the strut mount to the body of the car.

Step 5: Replace Struts and/or Strut Mounts

Hold the center spindle of the shock absorber with a pair of vice grips and use a 16mm box wrench to remove the nut. Slide the old strut mount off of the spindle noting the orientation and order of the paper gasket and the cupped metal washer.

Note: Larry and I both found that our tool sets did not come with 16mm sockets or box wrenches, for no apparent reason but to surprise unsuspecting mechanics mid-repair. Check yours before beginning.

This is the point at which you should replace either your struts, your strut mounts or both. Reassemble the strut assembly in the following order (from bottom to top):

• Strut
• Plastic Dust Shield
• Rubber Bumper
• Spacer
• Strut Mount
• Cupped Metal Washer (concave side up - i.e. "holding water")
• Lock Nut (use a new one)

Step 6: Reinstall Struts

Installation of the struts is the reverse of removal. Remember to use a fresh paper gasket between the top face of the strut mount and the wheel well (the gasket goes on the road-side of the body).

Secure the bottom of the strut using the old bolt. Use two fresh lock nuts to secure the top of the strut assembly to the body. Tighten all bolts appropriately (see sidebar for tightening torques).

That's it! You're done.