Knowledge Base
BMW Control Arms & Bushings — Complete Replacement Guide
BMW Control Arms & Bushings — Complete Replacement Guide
Overview
BMW's multi-link suspension uses multiple control arms per corner, each with rubber or hydraulic bushings. These bushings wear over time, degrading handling and ride quality.
Front Suspension Components
Lower Control Arms (Thrust Arms)
- Connect the wheel hub to the subframe
- Contain the main lower ball joint
- Most common wear item — bushings deteriorate, causing clunking and vague steering
- Replace in pairs (both sides)
Tension Struts (Compression Rods)
- Run forward from the lower control arm to the subframe
- Resist braking forces
- Bushings wear, causing vibration under braking
Upper Control Arms (Wishbones)
- E90+: Aluminum upper arms with pressed-in ball joints
- Ball joint wear causes clunking over bumps
- Replace entire arm (ball joint is not separately serviceable on most models)
Sway Bar End Links
- Connect the sway bar to the strut/control arm
- Ball joints wear, causing clunking on bumps and body roll
- Cheap and easy to replace (~€20-40 each)
Rear Suspension Components
Trailing Arms
- Main structural link from body to rear wheel hub
- Bushings wear, causing rear-end instability
- E46: Notorious for RTAB (Rear Trailing Arm Bushing) wear
Camber Arms / Toe Arms
- Adjustable on some models for alignment
- Bushings wear, causing alignment drift
Rear Subframe Bushings
- E46: Can crack the body around mounting points
- E90+: More robust but still wear over time
When to Replace
| Symptom | Likely Cause |
|---|---|
| Clunking over bumps (front) | Lower control arm bushings, end links |
| Vibration under braking | Tension strut bushings |
| Vague steering, wandering | Control arm bushings, tie rods |
| Clunking over bumps (rear) | Trailing arm bushings, end links |
| Uneven tire wear (rear inner) | Rear trailing arm bushings, camber arms |
| Rear-end feels loose | Subframe bushings, trailing arm bushings |
Recommended Brands
- Lemförder — OEM supplier, best quality
- Meyle HD — Heavy-duty aftermarket, good value
- TRW — OEM quality
- Powerflex — Polyurethane bushings (firmer, longer lasting, more NVH)
