2025 Kenworth T680 — Wheel Alignment Specifications

Quick reference

Note: Kenworth publishes preferred values and allowable ranges that vary by VIN, axle manufacturer (Meritor/Dana), GAWR, suspension (e.g., AG380/AG400/AG400L), and tire size. Always align to the OEM printout for your specific truck. This page does not list numeric targets to avoid conflicts with OEM service information.

Adjustability

Front (steer axle)

• Toe: Factory-adjustable at the tie-rod sleeve. This is the primary steering adjustment on the T680.
• Caster: Often adjustable on leaf-spring steer axles using tapered caster shims between the axle pad and the leaf spring. Availability and amount of correction depend on axle and spring pack configuration. Follow the axle manufacturer’s procedure and torque specs.
• Camber: Not factory-adjustable on forged I-beam steer axles (Meritor/Dana). If camber is outside the OEM range, correction is typically via approved offset kingpin bushings or by precision axle beam straightening/bending performed by a qualified heavy-truck alignment facility, only where permitted by the axle OEM. Do not slot spring seats or alter beam geometry outside of approved methods.
• SAI: Not adjustable. Used as a diagnostic angle to detect bent axle beams, twisted knuckles, or kingpin bore issues.

Rear (tandem drive axles)

• Thrust/axle alignment: Adjustable depending on suspension. Common Kenworth air-ride suspensions (e.g., AG400/AG400L) use eccentric cams, slotted trailing-arm brackets, or adjustable torque rods to square the axles to the chassis centerline and set thrust to near zero. Leaf-spring suspensions may require shim packs at the spring seats to correct axle skew.
• Toe: Not adjustable on solid rear drive axles; excessive rear toe indicates bent housings or mislocated axle seats that must be repaired/replaced.
• Camber: Not adjustable on solid housings; out-of-spec camber indicates housing bend or wheel/end issues.
• Individual drive-axle specifications (set-forward/set-back, wheelbase, ride height) affect the allowable thrust window—use the OEM chart for your suspension option codes.

Recommended adjustment hardware

Use components that match your VIN, axle model, and suspension option codes. Examples of commonly used hardware categories for Class 8 tractors like the T680 include:

• OEM caster shims and shim packs for Meritor or Dana I-beam steer axles (sized for your spring width and center bolt).
• Offset kingpin bushing kits (heavy-duty) when permitted by the axle OEM to correct minor camber/caster discrepancies.
• OEM or equivalent eccentric cam kits/adjustable washers for Kenworth AG-series trailing-arm brackets to set drive-axle thrust (verify by suspension model and serial).
• Adjustable/repair torque rods or bushings to fine-tune axle square on air-ride suspensions.
• Alignment shim packs for leaf-spring rear suspensions where OEM allows.

Avoid generic or mismatched hardware—improper parts can shift under load and cause rapid tire wear. Always recheck ride height (air-suspension leveling) before final measurements.

Symptoms of bad alignment

• Feathered wear on steer tires: Ribs feel sharp on one edge and smooth on the other when you "hand sweep" across the tread. Commonly caused by incorrect toe or thrust misalignment steering you off-center.
• One-shoulder or split shoulder wear on steers: Inside or outside edge wears faster. Can indicate camber error, cross-caster imbalance, or bent components. Also check wheel offset and ride height.
• River wear/wavy circumferential channels on steer tires: Often linked to incorrect toe and/or compliance in worn kingpins, tie-rod ends, or hub bearings.
• Diagonal/heel-toe wear on drive tires: Points to drive-axle skew (thrust angle not centered) or mixed tire diameters. Look for dog-tracking.
• Rapid cupping: Typically a combination of misalignment and worn shocks/bushings; verify suspension condition before and after alignment.
• Steering pull or off-center wheel: Can result from cross-caster or thrust misalignment; also confirm brake drag and tire conicity.

When to align

• After replacing steer or drive tires, wheels, or rotating steer tires.
• After suspension or steering service: kingpins, tie-rod ends, leaf springs, torque rods/bushings, airbags, or ride-height valve adjustments.
• After impact: potholes, curb or debris strikes, or collision repair.
• If ride height has changed (new airbags or leveled suspension) or if you observe irregular tire wear or dog-tracking.
• At regular intervals as part of preventive maintenance, especially for high-mileage linehaul service.

Typical alignment cost

Pricing varies by region, shop capability, and number of axles adjusted:

• Steer-axle (front) alignment: typically $175–300.
• Three-axle (tractor) alignment: typically $350–600.
• Additional charges apply for seized hardware, shim/cam kits, or bushing/kingpin repairs. A quality shop will include before/after printouts that reference the OEM preferred and allowable ranges for your VIN.

Find a trusted alignment shop on Repairius.