Apex Chassis ProLock Complete Steering Kit | DOM Steel | 2017-2026 Ford F-250/F-350 4WD | SKU: KIT375-STL

Brand: Apex Chassis | SKU: KIT375-STL | Material: Heavy-Duty DOM Steel | Lift Range: 2–6" | Gas & PowerStroke Diesel | Free Shipping | Affirm & Afterpay Available

You Built Your Super Duty For Punishment. Now Your Factory Steering Is Yielding.

You lifted your late-model F-250 or F-350 to tow heavy, haul hard, or conquer punishing trails. What you didn't plan for was the severe steering compromise. The vague tracking, the relentless bump steer, and that disconnected feeling at the steering wheel that turns high-speed trail runs or heavy towing into an exhausting battle.

That isn't a problem with your suspension lift. That is your factory steering linkage—engineered out of thin-walled, stamped components meant for stock pavement driving—flexing and bowing under the massive leverage of larger tires and altered suspension geometry. Under extreme trail impacts or high-tonnage towing loads, factory linkages don't just flex; they permanently deform, throwing your alignment out and accelerating tire wear.

The Apex Chassis KIT375-STL is the absolute final answer. This complete, maximum-duty steering overhaul combines both the tie rod and drag link into a unified, ultra-premium system. Engineered specifically for 2–6" lifted 4WD applications on the 2017–2026 Ford F-250 and F-350 Super Duty platform (P558 & P702 generations), this kit is built from high-tensile DOM (Drawn Over Mandrel) steel to provide maximum impact resistance and unmatched structural integrity where aluminum setups reach their mechanical limits.

The Obsidian Take

We stock the Apex Chassis KIT375-STL DOM steel kit because it represents the highest level of structural defense available for the modern Super Duty platform. While aluminum kits offer memory-flex properties, heavy-duty rock crawling, oilfield abuse, and maximum-capacity commercial towing demand the raw, unyielding density of thick-walled DOM steel. At a substantial 61 lbs, this is the heaviest, most robust steering assembly in the Apex lineup, explicitly engineered to absorb brutal, dead-on obstacles without buckling.

Apex completely replaces the weak, failure-prone factory adjustment sleeves with their patented ProLock™ mechanical keyway system. Securely anchored by dual-thread jam nuts and integrated set screws, this system physically locks your settings in place. It cannot back out, slip alignment, or loosen under sustained off-road shock loads or high-load highway towing. If you are running massive tires and pushing a 2017+ Super Duty to its limits, upgrading to this DOM steel system is mandatory to guarantee you never get stranded by a bent steering link.

⚠️ Solid Axle Geometry Fact: The manufacturer install sheets reference adjusting "caster, camber, and toe" post-installation. The 2017–2026 Ford F-250/F-350 4WD runs a solid front axle housing where factory camber is completely non-adjustable without aftermarket offset ball joints. This complete steering linkage overhaul directly dictates front toe-in/toe-out adjustments and centers the steering wheel tracking line.

⚠️ Unsprung Weight & Shock Mandate: Weighing in at 61 lbs combined, this kit adds substantial unsprung mass to your front axle. Factory or light-duty replacement shocks are mechanically insufficient to dampen these tracking forces. Upgrading to heavy-duty, performance-valved shocks or a high-end steering stabilizer is mandatory to properly control this assembly and prevent front-end feedback.

Confirmed Fitment Matrix

CRITICAL FITMENT NOTE: This kit is mathematically and geometrically optimized exclusively for the modern radius-arm P558 and P702 Ford Super Duty platforms.

❌ This Unit Does NOT Fit:

• 2WD Super Duty Trucks: Two-wheel-drive configurations use a completely different independent front suspension layout lacking a solid axle steering linkage.

• Ford F-450 / F-550 Commercial Chassis: Upgraded wide-track axles utilize different width profiles and taper dimensions.

• 2005–2016 Super Duty (P221 Platform): Previous generation steering geometry and taper angles do not match (Requires the Apex KIT370 series).

• Ford F-150 Platforms: Fully independent light-duty front suspension systems; completely incompatible.

Technical Specifications

Before You Order — 4 Fitment Checkpoints

This is a commercial-grade steering assembly operating under extreme loads. To eliminate checkout friction and installation-day delays, verify these four checkpoints:

1. Model Year & Generation: Confirm your Super Duty falls strictly between 2017 and 2026. This kit fits the P558 and P702 radius-arm platforms only; it will not fit 2016 or older trucks.

2. Drivetrain Validation: Ensure your truck is a true solid-axle 4WD configuration. 2WD models do not utilize a solid-axle drag link and tie rod layout.

3. Lift Profile & Angles: Tailored for 2–6" lifted builds. If installing on an unlifted, factory-height truck, you must carefully sweep the steering lock-to-lock to ensure drag link angles do not induce bump steer.

4. Dampening & Valving: Ensure your front shock package and steering stabilizer are premium aftermarket units rated for heavy unsprung mass. Stock shocks cannot control a 61 lb steering assembly over harsh terrain.

Professional Installation & Mechanical Notes

This is an intermediate-to-advanced installation due to the physical weight of the components. A professional alignment is not optional post-install.

• Mandatory Post-Install Alignment: Swapping your entire tie rod and drag link instantly alters front toe settings and steering wheel alignment. Do not operate at highway speeds until a professional technician conducts a full toe alignment. (Note: Camber is fixed on this front axle).

• Torque Specifications:

  • Castellated Nuts (Knuckles & Pitman Arm): Torque strictly to 70–90 ft-lbs, then advance the nut only enough to clear the window to insert the cotter pin. Never back off a torqued steering component to fit a cotter pin.

  • ProLock Jam Nuts: Torque precisely to Apex Chassis specifications to mechanically engage the internal locking wedge keyway.

• Track Bar Parallelism: For suspension lifts exceeding 4 inches, a track bar relocation bracket is highly recommended to keep your track bar and new drag link operating on parallel planes, eliminating geometry-induced bump steer.

INSTALLATION WARNING: Failure to run performance-valved shocks capable of controlling this 61 lb heavy-duty assembly can result in front-end feedback or premature stabilizer wear. Once installed, this unit is non-returnable.

Questions We Get Asked

Why choose DOM Steel over the Polished Aluminum Apex kit? While aluminum is excellent for memory-flex on standard trails, thick-walled DOM steel offers maximum absolute resistance to gouging and bending from sharp rocks. If your truck is a dedicated work horse, heavy tow rig, or regular rock crawler, the pure structural mass of DOM steel is the preferred option.

Will this steering kit work with my factory pitman arm? For suspension lifts between 2 and 4 inches, this kit integrates perfectly with the factory pitman arm. For lifts exceeding 4 inches, you must cross-reference your drag link angle with your track bar; an aftermarket dropped pitman arm may be required to keep them parallel.

Does this kit include both the tie rod and the drag link? Yes. The KIT375-STL is a complete steering system overhaul. It packages the ultra-heavy-duty DOM tie rod, the matching drag link, and all necessary ProLock high-misalignment greasable joint ends under a single SKU.

Can I install this on my 2025 F-350 Dually? Yes, provided your F-350 is a 4WD Single Rear Wheel (SRW) or Dual Rear Wheel (DRW) configuration on the standard platform. It will not fit F-450 or F-550 commercial chassis trucks due to their wider commercial front axle tracking.

Why Buy From Obsidian Forged Auto Supply

• Authorized Apex Chassis Dealer — Full manufacturer warranty protection with factory-direct product tracking.

• Free Shipping, Lower 48 — Rapid freight transit with zero hidden handling surcharges at checkout.

• Real Fitment Verification — Text (469) 407-7538 (SMS only) with your model year, lift size, tire dimensions, and shock setup before ordering. An Obsidian technician will manually audit your build parameters before your order ships.

• Premium Financing Available — Flexible, secure payment tailoring available via Affirm and Afterpay.

2017–2026 Ford F-250 / F-350 Super Duty 4WD. Maximum-Duty DOM Steel. Lock down your geometry. Add to cart.

Disclaimer

The technical and product information presented above is compiled from data provided directly by the component manufacturer. Obsidian Forged Auto Supply maintains a rigorous engineering audit workflow to ensure vehicle fitment compatibility; however, we are not responsible or liable for sudden manufacturer-driven specification updates, raw metadata changes, or accuracy discrepancies in the foundational data sheets provided by the manufacturer.

Unsure if your current aftermarket shocks or track bar relocation brackets are up to handling this 61 lb setup? Text your exact front-end components to (469) 407-7538 and we'll confirm it.