Ford Twin I-Beam Suspension Parts for the 1987 F350: A Complete Guide

The 1987 Ford F350 with Twin I-Beam suspension is a workhorse built for heavy loads and rough roads. Over time, the suspension components wear out, leading to poor alignment, excessive tire wear, and a harsh ride. Whether you're restoring a classic or keeping a daily driver on the road, knowing the right parts and how to choose them is essential. This guide covers the key components, what to look for when buying replacements, and practical advice for a successful suspension rebuild.

Understanding the Twin I-Beam System

Ford's Twin I-Beam suspension debuted in the 1960s and was used on F-Series trucks through 1996. The 1987 F350 uses a solid axle front suspension with two forged I-beam arms that pivot from the frame on bushings. Each beam independently controls one wheel, using a coil spring mounted on the beam. This design provides durability and good ride quality for a heavy-duty truck, but the pivot bushings, ball joints, and steering linkages are common wear points.

Key Components to Replace

When servicing the front suspension of a 1987 F350 with Twin I-Beam, focus on these parts:

Radius Arm Bushings

Radius arms connect the I-beams to the frame and control fore-aft movement. Worn bushings cause wheel shimmy and imprecise steering. You can choose from rubber, polyurethane, or heavy-duty synthetics. Rubber offers a quiet ride, while polyurethane provides firmer control and longer life. For a heavy truck like the F350, polyurethane is a popular upgrade but may transmit more road noise.

Coil Springs

The front coil springs support the vehicle weight and absorb impacts. Over time, springs sag, reducing ride height and load capacity. Standard replacement springs are available from brands like Moog, AC Delco, and Skyjacker. If you carry heavy loads or tow frequently, consider heavy-duty or variable-rate springs. Measure the free length and wire diameter before ordering, as F350 springs differ from lighter F-Series models.

Ball Joints and Tie Rod Ends

Ball joints connect the steering knuckle to the I-beams. Tie rod ends link the steering linkage to the knuckles. Both are critical for safe steering. For a 1987 F350, ball joints are pressed into the I-beam; some are bolt-on, but most require a press for removal. Moog and Spicer are reliable brands. Always replace ball joints in pairs and check the tie rod ends for play. A drag link adjustment may be needed after installation.

I-Beam Pivot Bushings

These bushings allow the I-beam to pivot up and down. Like radius arm bushings, they come in rubber or polyurethane. Worn pivot bushings cause driveline vibration and loose steering. Replacement requires removing the I-beam from the frame, which can be challenging due to rust or corrosion. Use penetrating oil and a ball joint press tool for safe removal.

Steering Stabilizer

Although not strictly a suspension part, a steering stabilizer reduces bump steer and dampens vibration. Many 1987 F350s came with a stabilizer from the factory. If yours is worn or missing, adding one improves steering control, especially with larger tires. Monroe and Rancho offer direct-fit units.

Choosing Quality Parts

When buying suspension parts for your 1987 F350, consider the following:

• OEM vs. Aftermarket: Original equipment parts from Ford are expensive but guaranteed to fit. Aftermarket brands like Moog, Motorcraft, and Duralast offer good quality at lower prices. Check the part numbers carefully; some F350 parts are unique due to the heavy-duty chassis.
• Material: For bushings, polyurethane outperforms rubber in longevity but is stiffer. For coil springs, choose a spring rate that matches your typical load. If you don't carry heavy loads daily, standard replacement springs suffice.
• Kit vs. Individual Parts: Some suppliers sell complete suspension kit that includes all bushings, springs, and hardware. This can save time and ensure compatibility. However, you may not need every component. Inspect each part individually before ordering a full kit.
• Brand Reputation: Stick with well-known brands that have a track record for heavy-duty trucks. Avoid no-name parts from unknown suppliers; the suspension on a 1987 F350 must be reliable under load.

Installation Considerations

Replacing Twin I-Beam suspension parts requires mechanical skill and the right tools. Here are some practical tips:

• Safety First: The front springs are under tension. Use a spring compressor to remove coil springs safely. Never use impact wrenches on bushings or bolts without supporting the vehicle properly.
• Alignment: After replacing any suspension component, the truck must be aligned. Caster and camber adjustments are made on the I-beam bushings or shims. A professional alignment shop with experience on solid axle Fords is recommended.
• Torque Specs: Use a torque wrench for all fasteners. Over-torquing can distort bushings or break bolts. The factory service manual provides exact torque specs for each component.
• Rust: On a 1987 truck, bolts are likely rusted. Apply penetrating oil several days before disassembly. Heat can help but be careful near fuel lines. Replace any damaged or rusty hardware with grade 8 bolts.

Final Recommendation

For most owners of a 1987 F350 with Twin I-Beam suspension, the best approach is to rebuild the front end systematically. Start by inspecting the radius arm and pivot bushings, ball joints, tie rod ends, and springs. Replace worn parts with quality aftermarket components from Moog or Motorcraft. Consider upgrading to polyurethane bushings for added durability, especially if you haul heavy loads. Pair the suspension work with new shocks, such as Bilstein or KYB, to maximize ride quality. After installation, get a professional alignment to ensure even tire wear and stable steering. With proper maintenance, a rebuilt Twin I-Beam suspension will serve another 30 years of hard work.