Toyota HDJ80 heavy-duty front radius arms with +6° caster correction
The front radius arms for Toyota HDJ80 with +6° caster correction directly replace the original arms without any modifications. They are recommended for suspension lifts up to +7 cm, compensating for axle rotation caused by the lift and restoring correct steering geometry.
Their geometry has been specifically engineered to correct the altered caster angle resulting from the lift while increasing suspension articulation freedom.
Caster correction is crucial on the front axle as it directly impacts directional stability, steering precision, and self-centering capability after cornering. With a suspension lift, the front axle rotates relative to its original position and caster decreases: these caster-corrected radius arms feature an integrated +6° correction to return geometry to an optimal condition for the new ride height.
Main Features
- Heavy-duty front radius arms for Toyota HDJ80
- Recommended for suspension lifts up to +7 cm
- +6° front caster correction
- Improved approach angle
- Greater clearance for oversized tires
- High-quality Italian polyurethane bushings
- High suspension articulation capability
- Structural steel load-bearing frame
- Main body CNC-cut from a single plate
- TIG-welded perimeter reinforcements
- Anti-corrosion galvanization
- Powder-coated finish
- Direct fitment on OEM mounting points
- Made in Italy
The kit includes:
- Pair of front radius arms
- Pre-installed polyurethane bushings
Fitment:
Why does a suspension lift alter the Toyota HDJ80’s caster angle?
When you lift the HDJ80 chassis, you increase the distance between the body and the wheel axle. Since the axle is connected to the chassis via the radius arms, this added distance forces the arms to angle downwards. As they push downward, they pull and rotate the front axle slightly forward on its axis.
This rotation alters the angle of the wheels (the caster angle), causing them to lose their natural alignment point. The resulting driving feel is similar to shopping cart wheels: the steering becomes light, wandering, and unpredictable, making the vehicle drift on straightaways rather than tracking straight automatically. Corrected radius arms rotate the axle back into its original position, fully restoring driving stability and safety.
+6° Caster and steering handling
The radius arms feature an integrated +6° caster correction built directly into their geometry.
This correction adjusts the front axle orientation relative to the arms, offsetting the rotation created by the lift and returning the steering axis to a more favorable angle.
A correctly set caster angle helps maintain:
- Greater directional stability;
- Improved steering self-centering;
- More precise steering response;
- More predictable road handling;
- Front geometry better aligned with the lifted suspension.
The correction is achieved directly through the shape of the radius arms and requires no modifications to the original mounting points.
Corrosion protection
Following fabrication, the radius arms undergo galvanization and are subsequently protected with a polyurethane powder-coat finish.
Galvanization protects the steel directly from corrosion, while the outer coating adds a second protective barrier against water, mud, and environmental hazards.
This dual-layer protection is particularly critical for components mounted beneath the vehicle that are constantly exposed to harsh conditions.
Direct fitment on OEM mountings
The radius arms are designed for direct replacement of the original components using the factory Toyota HDJ80 mounting points, requiring no structural modifications to either the chassis or axle.
Frequently Asked Questions
Which suspension lifts are Toyota HDJ80 +6° caster radius arms recommended for?
They are recommended for suspension lifts up to +7 cm.
What is the purpose of the +6° caster correction?
It offsets the front axle rotation caused by the lift and restores steering geometry for improved stability, precision, and self-centering capability.
Do these radius arms help correct the "banana effect" (bowing) on front coil springs?
Yes. Correcting the caster adjusts the axle rotation, which in turn realigns the spring perches. By returning the axle to a proper angle, the coil springs operate much more vertically compared to using stock radius arms on a lifted setup.
Are the radius arms supplied complete with bushings?
Yes. The radius arms include all bushings, for both axle-side and chassis-side mounts.
The result is a component designed for HDJ80 builds where geometry correction, steering precision, heavy-duty durability, and suspension travel must work seamlessly together.
