SPL Parts rear lower trailing arms replace the flimsy stamped steel factory arms with 6061-T6 billet aluminum, anodized black and assembled with zinc plated class 10.9 metric hardware. Each arm weighs 0.75 lbs (0.34 kg), roughly 35% less than the OEM piece, so unsprung mass at the rear corner drops and the dampers have less weight to control over bumps. Under hard acceleration and braking the stamped OEM arm deflects several millimeters, which together with rubber bushing flex introduces rear bumpsteer and instability; the billet section holds its geometry instead. SPL rates the arms as having no impact on NVH.
| Type | Rear lower trailing arms (SPL Parts) |
| Position | Rear, lower |
| Material | 6061-T6 billet aluminum, zinc plated class 10.9 metric hardware |
| Finish | Anodized black |
| Weight | 0.75 lbs (0.34 kg) per arm, approximately 35% lighter than OEM |
| OEM Replacement | 33322406291, 33326763477 |
| Quantity | Pair (2 arms, one pair per vehicle) |
| Part Number | SPL RTR E9X |
Documents: Installation Instructions (PDF)
This part fits:
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2008-2013 | BMW | 1 Series (E81/E82/E87/E88) | All |
| 2011 | BMW | 1 Series M Coupe (E82) | All |
| 2006-2013 | BMW | 3 Series (E90/E91/E92/E93) | All |
| 2008-2013 | BMW | M3 (E90/E92) | All |
Shipping: In-stock orders placed before 3 PM EST ship the same day, and everything else ships within 24 hours. Standard, expedited, and overnight options are available at checkout. Backordered items ship as soon as we get them back in stock. Contact us for lead times. See the full Shipping Policy.
Returns: 30-day returns on new, unused items in original packaging. See the full Refund Policy.
