SPL Parts Adjustable Front Caster Rod Monoball Bushings for Toyota GR Supra A90 & BMW Z4 G29 | FKS Series FK 1in Spherical Bearings

Adjustable Front Tension Strut Spherical Bearing Kit for Toyota GR Supra A90 and BMW Z4 G29

Dial in laser-sharp steering feel, rock-solid braking stability and repeatable alignment control with the SPL Parts FKS Series front tension arm rear bush conversion. This upgrade replaces the factory rubber isolators with motorsport-grade 1 inch FK PTFE-lined spherical bearings and precision offset spacers, giving you accurate caster tuning and a connected front end on road and track.

If you want crisp turn-in, improved on-centre confidence and consistent tyre contact under load, this is the proven solution. We have fitted this kit to multiple Supra A90 and Z4 G29 builds and customer feedback has been outstanding for steering precision, stability and tyre wear after a proper setup.

Why this bearing conversion is a game changer

• Replaces soft compliance bushes with articulating race-spec joints for zero play and direct feedback
• Offset spacers provide approximately plus or minus 4 degrees of caster adjustment for fine tuning handling balance
• Holds alignment during hard braking, rapid direction changes and kerb strikes
• Transforms front end response for fast road, time attack and track day use
• Built for durability with low-friction, self-lubricating liners for long service life

Technical highlights

• FK 1 inch PTFE-lined spherical bearings from the FKS Series
• 6061-T6 aluminium housings with knurled outers
• CNC machined offset spacers for precise caster correction
• Sold as a pair
• OEM control arms not included
• Made in the USA

Vehicle fitment

• Toyota GR Supra A90 2020+
• BMW Z4 G29 2019+

Part number

SPL CRB G29

Installation and setup

Professional fitting is recommended. Always carry out a full four-wheel alignment after adjusting caster.

Want it installed by specialists We can fit and align your car at MJ Modifications in Warwickshire. Request a quote at info@mjmodifications.co.uk.

What owners are saying

After installing this kit on Supra A90 and Z4 G29 builds, customers report noticeably cleaner steering inputs, greater high-speed confidence and more even tyre wear once set up correctly.

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