Aug 022011

This past weekend I tackled a known weakness of the BMW E36 3 series, the rear shock mounts (RSMs). (It’s also an issue to a lesser degree for the E46 model). These mounts connect the rear shocks to the car frame, and can prematurely fail. In the worst cases the top of the shock can actually tear through the sheet metal at the top of the wheel well.

So replacing/reinforcing your RSMs is a smart preventative move. Last year I purchased some heavy duty RSMs from Meyle and some reinforcement plates designed for the BMW Z3, but hadn’t done the job.¬† It was on the to-do list, but with less than 53K miles on my M3 it wasn’t yet mission critical.

New and old mount

But when fellow enthusiast¬† and DC area native Darrold Johnson mentioned he had just done the job on his beautiful 1998 M3 convertible and he had access to a shop, it was time to pull the trigger. As retired military, Darrold has access to the Auto Skills Shop on the grounds of Fort Meade in Maryland. It’s a veritable paradise for the DIYer, with multiple bays, lifts and complete sets of tools at very reasonable rates.

A few observations for fellow DIYers on this job:

  • Some online instructions say you must remove the rear speakers to access the RSMs. This wasn’t the case for me — you only have to remove the carpeting in the trunk
  • Be patient pulling the carpet out — don’t rip the material or break the two clips behind the rear seats
  • It’s a good idea to support the suspension prior to removing shock to relieve pressure and keep in same position for when you’re ready to reattach
  • There is no information I could find on how much to torque the RSM bolts in the Bentley manual — just do them nice and tight
  • It’s a PITA trying to keep a light colored interior like my dove gray clean during this job

Any time you put your car up in the air it’s a good idea to check some little things. So I also did an oil change, checked all tires and the spare, and zip-tied a loose underpanel on the passenger side. Three of the four tires were hard to remove, so I also put some anti-seize on the hubs.

Huge thanks to Darrold for his time and counsel, and for access to the Auto Skills Shop. A resource like that makes many DIY projects feasible, and I hope to be writing about using the shop again in this blog.

UPDATE – had a good discussion thread about this in the LinkedIn BMW Group, and the torque for the RSM bolts is just 17 lbs. Careful not to overdo it. This number comes from the good online resource

View from below left wheel

Supporting the suspension prior to removing shock assembly

Target acquired, after removing carpet from trunk

Replaced -- note reinforcement plate below mount

  One Response to “Rear Shock Mount Replacement on an E36 M3”

  1. Rear shock mount replacement on an E36 M3 — this is a known weakness of the BMW E36 model.

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