Hurrey's Caster · Pinion · Wheelbase Wizard
Technician-facing calculator for solid-axle Jeep / Bronco platforms using upper & lower control arm length.
Auto-fills OE specs, tracks wheelbase shift, and shows live caster / pinion behavior. Print to attach this to the RO.
Vehicle & Customer
Select chassis, pre-fill OE specs, then override as needed.
FRONT + REAR · SOLID AXLE
Tip: Use preset to establish stock reference, then adjust “New” arm lengths only.
· Vehicle preset: JL 4-Door · Wheelbase 118.4" · OE caster 6.0°
Baseline Geometry & Tire Package
Wheelbase and alignment targets, plus tire diameter for ride height / length.
OE BASELINE
Wheelbase delta
0.00" change
Caster vs OE target
0.0° offset
Front pinion delta
0.0° change
Rear pinion vs target
0.0° offset
Tire diameter is used to approximate ride height gain and overall bumper-to-bumper length change. It does
not change wheelbase.
Tire diameter delta / ride height
0.00" dia change
Stacked tire visualization: inner ring = old diameter, outer ring = new diameter (scaled relative).
Helps quickly communicate ride height and overall length change to the customer.
Control Arm Lengths
Enter OE (Old) and Adjusted (New) lengths for front & rear uppers/lowers. This drives caster, pinion, and wheelbase change.
OLD / NEW ON SEPARATE LINES
Front Axle – Driver side reference, passenger assumed matched.
Autofilled from OE (stock reference).
Autofilled from OE (stock reference).
Rear Axle – Driver side reference, passenger assumed matched.
Autofilled from OE (stock reference).
Autofilled from OE (stock reference).
Visual Axle Rotation & Pinion / Caster
Conceptual only – shows axle / pinion behavior based on arm length change. Not a replacement for an alignment rack.
REFERENCE ONLY
Rear Axle Rotation & Pinion
Pinion: 0.0°
Left: Axle tube rotation
Right: Pinion vs driveshaft
Front Axle Caster & Pinion
Caster: 0.0° · Pinion:
0.0°
Left: Axle tube & caster rotation
Right: Caster arrow at knuckle
Printable Alignment Summary
Mirrors the fitment tool style with wheelbase, caster / pinion, tire data and parts info. This is what you hand to the customer.
SUMMARY · RO ATTACHMENT
Shop Disclaimer: This calculator is an engineering aid only and does not replace a calibrated alignment
rack, straight-edge verification, pinion angle measurement tools, or on-road validation. All values are approximations based on
control arm length change and typical solid-axle geometry. Final caster, camber, toe, thrust angle and pinion angles must be
verified and adjusted by a qualified technician. Modified vehicles, aftermarket components and tire sizes may require settings
outside OE targets. Customer is responsible for re-torque of suspension fasteners and wheel lugs after 50–100 miles and routine
inspection after off-road use.
Need help deciding what fits your build?
Use Hurrey's tools and reference pages to narrow down fitment, compare options, and talk to the shop before ordering.
Fitment Tools
Offset, tire, and clearance calculators used to plan builds more confidently.
Fitment Library
Vehicle-specific wheel and tire reference data for faster research.
Services
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Contact the Shop
Reach out if you want a second opinion before checking out or booking service.