Powerflex PFF5-5401G Poly Bushes/Bushings Front Lower Control Arm Rear Position (Caster Adjustable) for BMW Z4 G29 2018+ – Tension Strut/Thrust Arm/Wishbone Rear Bush Set, Radius Rod to Chassis Compliance Bush, Caster Correction Alignment Upgrade

Part number: PFF5-5401G

Transform front-end precision on your 2018-on BMW two-seater with this premium polyurethane tension strut solution. Designed for the rear position of the front lower arm, this upgrade controls fore and aft movement under braking and cornering, tightens steering response and keeps alignment stable for confidence on B-roads and dual carriageways alike.

Built around a tough Black 95A polyurethane compound, paired with hard-anodised aluminium outer shells and a CNC machined stainless inner sleeve, this kit delivers a dramatic stiffness increase of around 300 percent versus the standard rubber item. The result is crisper turn-in, better high-speed stability and braking composure, plus reduced shoulder wear thanks to more consistent geometry.

PFF5-5401G also provides approximately ±0.75 degree of caster tuning on the car, letting you dial in sharper response or correct a steering pull without resorting to complex hardware swaps. Our team has fitted these on multiple customer cars and the feedback has been overwhelmingly positive for fast-road use and daily driving.

• Application focus: Road and fast-road handling upgrade
• Adjustment: On-car caster fine-tuning of about ±0.75 degree
• Construction: Black 95A polyurethane, anodised aluminium shells, CNC stainless sleeve
• Performance gains: Sharper steering feel, improved braking stability, reduced brake dive, better corner exit traction
• Longevity: Increased durability vs OE rubber and more consistent alignment to help extend tyre life
• Pack contents: 2 bushes
• Diagram reference: 1

Also referenced by enthusiasts as: front lower control arm rear bush, thrust arm bush, tension strut mount, wishbone rear bush, radius rod to chassis bush, compliance bush, caster correction kit, alignment adjuster, handling upgrade for BMW roadster.

Replaces OE numbers: 31106878587, 31106878588, 48640-WAA02, 48620-WAA02

Looking for a fit-and-forget suspension refresh that makes your car feel tighter, more accurate and more stable without harshness typical of solid mounts? This Road Series solution from POWERFLEX hits the sweet spot for real-world performance and value.

Professional fitting
We recommend installation by MJ Modifications in Warwickshire. Email info@mjmodifications.co.uk for a fitting quote and availability.

Notes: PFF5-5401G is the adjustable variant in this family. PFF5-5401 and PFF5-5401GBLK are related references within the same platform, with PFF5-5401/5401G measured at approximately 300 percent stiffer than the factory bush.