SPL Front Tension Rods / Caster Rods – BMW E8X / E9X / F2X / F3X / F8X & Toyota GR Supra / BMW Z4 G29

OVERVIEW

SPL Parts Front Tension Rods (TR) — the caster rods — give a wide range of front caster adjustment for precise alignment, sharper turn-in and the ability to correct side-to-side caster variance. Low friction FK spherical bearings replace the large, soft factory rubber bushing that lets the wheel move backwards under braking, and anti-dive geometry can be tuned with the supplied stainless steel spacers.

The BMW E9X / F8X and F2X / F3X rods are billet 2024 aluminum hex links, CNC machined and gun drilled to cut unsprung weight, black anodized, with SPL's exclusive 360-degree rotating clamp and blue anodized titanium hardware. FK rod ends from Connecticut use the upgraded, hardened JMX housing with a chemically bonded PTFE liner for strength and quiet articulation.

The GR Supra / Z4 G29 version uses 6061-T6 billet aluminum arms, 360-degree clamps and clevis with a hollow billet trailing link and a 4140 chromoly clevis stud, weighing 4.24 lb per side. Its caster adjustment increases camber gain with steering angle and improves self-centering, and the adjustable wheel location helps clear tires and set track width while preserving bumpsteer. Supplied 6061-T6 spacers fine-tune anti-dive to maintain splitter height or front travel.

SPECS

• Wide range of front caster adjustment; anti-dive tunable with stainless or aluminum spacers
• BMW: gun drilled, black anodized 2024 aluminum hex links; 6061-T6 aluminum 360-degree Rotating Clamp; blue anodized titanium socket head cap screws
• BMW: hardened JMX high misalignment three-piece Teflon-lined FK rod ends; PTFE liner rated −65°F to 325°F
• BMW: ASTM A574 socket head cap bolts, minimum tensile strength 170,000 psi
• G29: 6061-T6 billet aluminum arms, 360-degree clamps, clevis and hollow trailing link, black anodized; 4140 chromoly clevis stud; zinc plated class 10.9 metric hardware; Ti-6Al-4V 1/4"-20 titanium screws
• G29: 4.24 lb (1.92 kg) per side
• Sold as a pair (one pair per vehicle)
• Made in the USA

PARTS INCLUDED

• Two SPL Parts adjustable front tension / caster rods with rotating clamps, FK rod ends and titanium hardware
• Anti-dive adjustment spacers
• Complete kit as supplied by SPL Parts; see the installation instructions for the full bill of materials

TECH RESOURCES

Additional Parts Required

• Four-wheel alignment after installation — mandatory. Caster and toe both change when the rods are fitted.
• Professional installation is recommended; these are safety-critical suspension components.
• Corner weighting is recommended for track use.
• A 3/16" allen key is required to lock the rotating clamps; the installer supplies this.
• To use the full caster range on a lowered car, pair these with adjustable front lower control arms: SPL Front Lower Control Arms – BMW E8X / E9X / F2X / F3X / F8X / G2X or the SPL Front Lower Control Arms – Toyota GR Supra A90 / BMW Z4 G29.
• SPL recommends a quality coilover with suitable spring rates on the G29 / Supra to keep NVH in check.

Installation

• SPL Parts SPL TR E9X front tension rods — installation instructions (PDF)
• SPL Parts SPL TR F3X front tension rods — installation instructions (PDF)
• SPL Parts SPL TR G29 front caster rods — installation instructions (PDF)

Notes

• SPL TR E9X and SPL TR F3X will not fit xDrive / AWD cars. Rear-wheel drive only.
• The G8X M3 / M4 version is listed separately: SPL Front Tension Rods – BMW M3 / M4 (G8x).
• SPL TR G29 replaces BMW 31 10 6 878 587 / 31 10 6 878 588 and Toyota 48620-WAA02 / 48640-WAA02.
• Expect more harshness over rough roads and hard bumps, slightly more road noise and a greater chance of tramlining; ride on smoother roads still improves over stock.
• Price is for parts only; labor and alignment are not included.
• Confirm your exact model, chassis code and drivetrain with Speed Logic before ordering.

PART NUMBER

• SPL TR E9X — E82 / E88 135i and 1M, E90 / E92 / E93 335i, F80 M3, F82 / F83 M4, F87 M2 (RWD only)
• SPL TR F3X — F2X / F3X 2, 3 and 4 Series (RWD only)
• SPL TR G29 — Toyota GR Supra A90, BMW Z4 G29

VEHICLE APPLICATIONS