The ReadyLIFT 2.5"-4" Tubular Radius Arm Kit brings the front radius arm geometry back in line after lifting. Correct arm geometry helps caster, steering feel and tire wear on a lifted truck. ReadyLIFT kit 77-27400 is engineered for the 2017-2022 Ford F-250 Super Duty and F-350 Super Duty.
What's Included:
| Kit components (ReadyLIFT) |
|---|
| Radius Arm, Left, Assembled |
| Radius Arm, Right, Assembled |
| Cam Bolt Kit |
Alignment, headlamp aiming and ADAS recalibration are not included.
Features
Corrects lifted geometry
Lifting a solid front axle changes the radius arm angle. These parts return the geometry toward the factory design.
Made for Super Duty
Every part in this range is engineered for Ford Super Duty 4WD trucks.
Built heavy for duty
Arms and brackets are built for the use and weight heavy-duty trucks put on their front suspension.
Supports larger tires
Correct arm geometry keeps axle location in check as bigger tires go on a lifted truck.
Upgrade for lifted trucks
The parts are aimed at trucks already running a leveling or lift kit.
Fitment & Compatibility
Ford
| Years |
Model |
Notes |
| 2017-2022 |
F-250 Super Duty |
4WD only; Diesel engine only |
| 2017-2019 |
F-350 Super Duty |
4WD only; Diesel engine only |
| 2020 |
F-350 Super Duty |
Not for Tremor trim; 4WD only; Diesel engine only |
| 2021-2022 |
F-350 Super Duty |
4WD only; Diesel engine only |
Fit guidance: Fits: 2017-2022 Ford F-250 Super Duty/F-350 Super Duty, with the qualifiers shown. Check your vehicle's trim, drivetrain and factory suspension against these notes before ordering.
Specifications
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Brand: ReadyLIFT
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Warranty: ReadyLIFT No Hassle warranty, original purchaser; bushings up to 1 year
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Install time (ReadyLIFT estimate): about 3 hours (give or take 0.5), alignment and wheel mounting extra
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Shipping weight: 69 lb
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Kit type: Control arms
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Install difficulty: Professional install recommended
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Part number: 77-27400
Installation
Type: radius arm upgrade · Install: per-vehicle, see each kit's install sheet · Afterward: alignment, headlamp aim, ADAS check
This kit installs using the steps in ReadyLIFT's instructions for this truck. Plan on a wheel alignment after installation and have headlamp aim checked. Vehicles with camera, radar or sonar driver-assistance systems need those systems checked and recalibrated, which can require dealer tools. ReadyLIFT recommends installation by a certified mechanic and says to read the full instructions before starting.
ReadyLIFT estimates about 3 hours for this kit, give or take 0.5 hours, not counting the alignment or mounting wheels and tires.
Resources
An installation guide for this part number is not available to download. Our team can answer installation questions before you order; contact us with the part number.
Warranty, Shipping & Returns
Warranty. ReadyLIFT backs this product with its No Hassle warranty for the original purchaser: if a part breaks or arrives defective, ReadyLIFT ships a replacement, and a claim starts with a call to 800-549-4620. Wear items such as shocks, ball joints and bushings are covered for up to one year. Discontinued, clearance and outlet items are excluded, as are labor, installation charges and consequential vehicle damage. Shipping. The carrier and ship method are set by the size and weight of the cartons when the order is placed; larger kits ship by freight. Inspect on delivery. Check every box and part against the kit component list when it arrives, and report any shortage or shipping damage before installation begins.
Returns. Unused items in their original packaging can be returned within 30 days of delivery. If an item arrives damaged, defective or wrong, return shipping is on us. See our Returns & Refunds Policy, or email support@prestigetruck.com with any question.
About ReadyLIFT
ReadyLIFT Suspension started in 2006 with one goal: give truck and SUV owners more tire clearance and a better stance while keeping the ride and handling their vehicle had from the factory.
What began as a practical option to traditional big lifts now spans front leveling kits, SST mild lifts, full big lift systems, premium coilover packages, upper control arms and Falcon shocks for popular trucks and SUVs.
Wheel Pros bought ReadyLIFT in 2018, and in August 2026 the brand joined Bestop Premium Accessories Group, which plans continued investment in engineering, product development, manufacturing and customer support.
