Make your 1979-2004 Mustang’s performance to the next level with QA1 Adjustable Upper Trailing Arms (Rear Control Arms). Engineered for enhanced durability and precision, these control arms are a must-have upgrade for any Fox Body or SN95 Mustang.
Pinion Angle Adjustment for Lowered Vehicles
Lowering your Mustang? Proper pinion angle adjustment is crucial for preventing drivetrain wear and ensuring smooth operation. QA1’s Rear Upper Trailing Arms make this adjustment easy with their aluminum hex design, allowing you to fine-tune the pinion angle directly on the car. Achieving the correct angle also helps prevent issues like wheel hop and ensures optimal performance and ride quality.
Minimize Rear Suspension Bind
Designed to reduce rear suspension bind, these control arms enhance your Mustang’s rear suspension movement, resulting in better traction, a smoother ride, and consistent performance every time you hit the road.
Thoughtful, High-Performance Design
Built with high-strength, low-bind construction, QA1’s Upper Trailing Arms come equipped with durable polyurethane bushings, replacing the soft OE differential bushings. This upgrade provides improved stability and responsiveness.
Easy Bolt-In Installation
With a bolt-in design, these trailing arms are quick and easy to install, requiring no complicated modifications, making them the perfect choice for a straightforward performance boost.
Proudly Made in the USA
QA1 products are proudly manufactured in Lakeville, Minnesota, ensuring top-tier quality and craftsmanship.
Features & Benefits:
- Durable Construction: High-strength design reduces suspension bind for reliable performance
- Aluminum Hex Design: Allows for easy, on-car pinion angle adjustments
- Improved Suspension Travel: Reduces friction for smoother movement
- Polyurethane Bushings: Enhance stability by replacing softer OE bushings
- Hassle-Free Installation: Simple bolt-in process with no extensive modifications needed
- Made in the USA: Crafted with precision for quality you can trust
Fitment Notes:
- Sold as a pair
- Must re-use factory bushing shells
- Compatible with factory rear end housings
Installation Instructions Summary for QA1-5255 Adjustable Trailing Arms (1979-2004 Mustang)
Tools and Supplies Required:
- Floor Jack
- Jack Stands
- Torque Wrench
- Tire Chocks
- 18mm Socket and Wrench
- Lug Wrench
- Blue Loctite™
- Grease Gun
Step-by-Step Instructions:
- Prepare the Car:
- Place the car on a level surface and secure tire chocks in front and behind the front tires.
- Support the rear of the car with jack stands and remove the rear wheels.
- Position a floor jack under the differential to relieve tension from the trailing arm bolts (do not lift the car off the stands).
- Remove Stock Trailing Arms:
- Remove the rear bolt from either trailing arm using an 18mm socket and wrench. Take note of the bolt’s direction.
- Remove the front bolt and detach the trailing arm.
- Clean the frame at the trailing arm pivot area using a wire brush.
- Install Differential Bushing:
- Remove the inner sleeve from the differential bushing and clean the bushing shell.
- Lubricate the inside and flange of the OE bushing shell with the supplied grease.
- Install the new polyurethane bushing into the axle and insert the greased steel sleeve.
- Install QA1 Adjustable Trailing Arms:
- Install the new trailing arms with the grease fittings facing downward. Re-use the factory front bolt and apply one drop of blue Loctite™ before torquing to 70 lb. ft.
- Attach the trailing arm to the axle using the provided bolt, washers, and nut. Apply Loctite™ and torque to 70 lb. ft.
- Use a grease gun to lubricate the front bushings.
- Adjust Pinion Angle:
- Adjust the pinion angle by loosening the jam nuts and turning the aluminum adjuster sleeve. Ensure both arms are adjusted evenly and the spherical ball is straight and parallel with the housing.
- Secure adjustments with Loctite™ on the threads.
- Final Checks:
- Re-torque all bolts after the first 10 miles of driving. Check jam nuts periodically for tightness.
Important Notes:
- Full instructions with color images are provided with purchase.
- QA1 adjustable trailing arms come pre-assembled and ready for installation.
- Re-torque all bolts periodically to maintain performance and safety.
For more detailed guidance, refer to the complete installation manual included with your purchase, featuring color images to assist in the process.
