Porsche 911, 996 / 997 Rear Upper Control Arm Outer Bushings 22 mm
Porsche Suspension Bushings by PowerFlex
Let’s face it, suspension bushings on a Porsche can endure high stress, lateral loads, torsional twist, and thermal cycling, often in harsh conditions with very little maintenance or lubrication. With over 20 years of hands-on experience restoring and upgrading vintage Porsche components, PMB Performance is proud to partner with PowerFlex to address these demands with their modern solutions.
Porsche 911, 996 / 997 Rear Upper Control Arm Outer Bushings 22 mm
The Porsche 911 models from the 996 (1998-2004) and 997 (2005-2012) generations feature the Rear Upper Control Arm Outer Bushings - 22 mm as a key element of their sophisticated rear suspension systems. These bushings, sized at 22 mm and typically made of rubber or enhanced polyurethane, are positioned at the outer mounting points of the rear upper control arms, linking them to the chassis or wheel carrier. They play a crucial role in maintaining alignment, absorbing road shocks, and ensuring precise handling during cornering. Over time, wear from spirited driving or environmental exposure can cause these bushings to degrade, resulting in vague steering feel, noise, or uneven tire wear. Replacing them with high-quality bushings is essential for enthusiasts aiming to preserve the sharp, balanced performance that defines these water-cooled 911s.
The Problem with OEM Bushings
Porsche OEM bushings use a rubber compound—typically 60-70 Shore A hardness—that degrades over time. Age and exposure soften it, dropping stiffness by up to 40% within 5-10 years (depending on climate and use). Many aftermarket rubber bushings are even worse as they hit the market with little or no “anti-ozonates” in the compound. This increases compliance, allowing unwanted suspension movement. For vintage Porsches like 356’s, 911’s, 914’s, or 944’s, worn rubber means sloppy geometry, camber and toe shift under load, leading to uneven tire wear, brake shimmy, and vague steering. PMB’s decades of working on and restoring these cars confirms that bushings can be the primary culprit in that “old car” looseness.
The PowerFlex Solution
PowerFlex bushings tackle this with a proprietary polyurethane compound, formulated at 80-85 Shore A hardness—25-30% stiffer than fresh OEM rubber. Unlike generic urethanes that are prone to squeaking or harshness, PowerFlex tunes the polymer’s damping properties to match rubber’s noise absorption (NVH levels within 5 dB of OEM). The result: tighter control over suspension articulation, caster and camber shifts drop by ~20% under 0.8g cornering loads without sacrificing ride quality.
Even new Porsches can gain from PowerFlex’s design. Factory rubber starts compliant; PowerFlex’s higher stiffness and resistance to deformation (tensile strength ~20 MPa vs. rubber’s ~10 MPa) sharpen response from day one. For vintage restorations, PMB’s experience proves these bushings restore precision lost to decades of wear.
Material & Design Specs
- Polyurethane: 80-85 Shore A, cured to a Tg above 200°F for heat stability.
- Stiffness Gain: 25-30% over new rubber, verified via static load testing.
- Fitment: Modeled from OEM Porsche bushings, tolerances ±0.1mm, no mods needed.
- Options: Street (functional finish) and Heritage (dark grey, OEM-look coating).
Why PowerFlex with PMB?
- Durability: Polyurethane resists ozone and UV cracking—lifespan triples rubber’s.
- Control: Reduces suspension play, cuts tire wear, stabilizes braking.
- Experience: PMB’s 20 years with vintage Porsche 914s, 911s, and 944s ensure fit and function.