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SPL

SPL Parts Monoball Front Lower Control Arm Inserts (Compression/Thrust/Radius/Caster/Tension Rod Bushings) - Toyota GR Supra A90 (MK5) & BMW Z4 G29 - Spherical Pillowball Bearings, Fixed Geometry Non-Adjustable - CRBN Pair

SPL Parts Monoball Front Lower Control Arm Inserts (Compression/Thrust/Radius/Caster/Tension Rod Bushings) - Toyota GR Supra A90 (MK5) & BMW Z4 G29 - Spherical Pillowball Bearings, Fixed Geometry Non-Adjustable - CRBN Pair

£454.86
£478.80 £454.86
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SPL Performance Monoball Compression Arm Inserts for Toyota GR Supra A90 and BMW Z4 G29

Transform steering feel and front-end precision with SPL’s fixed-geometry monoball inserts for the forward position of the front lower control arm. By replacing the soft OE rubber with motorsport-grade bearings, this kit removes squish and flex in the front radius arm area for razor-sharp response, repeatable alignment under load and confidence-inspiring stability on fast road and track days.

We have installed these in-house and the difference is immediate: crisper turn-in, more consistent braking stability and clearer feedback through the wheel. Our customers love the upgrade for its quality and the way it tightens up the front end without the vagueness of factory bushes.

Why this upgrade

  • Replaces the forward bush in the front lower arm with a true monoball for minimal deflection
  • Keeps geometry stable under braking and cornering for predictable handling
  • Sharper on-centre feel and improved high-speed confidence
  • Fixed design for OEM-like setup with race-car precision
  • Ideal for fast-road builds, track-day use and performance-focused daily drivers

Engineering details

  • Massive 1 inch FK Racing Bearings with PTFE liners for low friction and long service life
  • CNC-machined 6061-T6 aluminium bearing carriers with knurled outer for a secure press fit
  • FKS Series specification for smooth articulation and durability
  • Made in the USA
  • Sold as a matched pair

Vehicle fitment

  • Toyota GR Supra A90 - 2020 onward
  • BMW Z4 G29 - 2019 onward

Who will benefit

If you are chasing more direct steering, reduced braking dive-induced geometry change and a planted front end on your Supra A90 or Z4 G29, this is the go-to front arm upgrade. Perfect alongside coilovers, uprated anti-roll bars and performance alignment settings.

Installation and support

Professional fitting is recommended. MJ Modifications in Warwickshire can supply and install these inserts and carry out alignment. Request a fitting quote at info@mjmodifications.co.uk.

Part number

SPL CRBN G29

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