Superlift 11884 5/8x3-1/4x16 Square U-Bolt Kit 4-Pack w/Hardware Universal Fits

Vehicle Fitment

• Universal / Semi-Universal - no vehicle-specific fitment required
• Suitable for any truck, Jeep, or SUV with a square U-bolt mounting configuration and leaf spring axle width requiring 3-1/4 in. inside width and 16 in. leg length
• Verify axle tube diameter and spring pack width against bolt dimensions before ordering

Fitment Notes

• Shape: Square (flat-bottom U-bolt for square axle housings or perch plates)
• Rod diameter: 5/8 in.
• Inside width: 3-1/4 in. (3.25 in.) - measure across the inside of the axle housing or perch
• Leg length: 16 in. - confirm adequate thread engagement below spring plate with your specific spring pack and lift block stack
• Thread type: National Fine (NF), Class 2A
• Commonly used in Dodge Ram HD (Dana 70/80 axle) and other heavy-duty full-size truck applications requiring long, large-diameter square U-bolts

Features

• Manufactured from low alloy, high-strength steel delivering 115,000 PSI yield strength and 133,000 PSI tensile strength - engineered for the clamping loads demanded by lifted suspension systems
• Square profile seats correctly against flat axle perches and spring plates, preventing rotation and ensuring uniform clamping force
• National Fine Class 2A thread form provides consistent torque-to-clamp-load relationship and resistance to vibration loosening
• Anti-corrosion zinc or black e-coat finish protects against rust and oxidation in off-road and winter driving conditions
• Aircraft-type nylon-insert locking nuts resist vibration-induced loosening under sustained off-road use
• Phosphate-coated, heat-treated extra-thick washers distribute clamping load evenly across the spring plate
• Made in the USA
• Limited lifetime warranty against defects in materials and workmanship

Specifications

• Brand: Superlift Suspension
• Part Number: 11884
• Shape: Square
• Rod Diameter: 5/8 in.
• Inside Width: 3-1/4 in. (3.25 in.)
• Leg Length: 16 in.
• Thread Type: National Fine (NF), Class 2A
• Yield Strength: 115,000 PSI
• Tensile Strength: 133,000 PSI
• Finish: Zinc or Black E-Coat (anti-corrosion)
• Country of Origin: USA
• Quantity: 4 U-Bolts per kit

Included Components

• 4x Square U-Bolts - 5/8 in. x 3-1/4 in. x 16 in.
• 8x Aircraft-type nylon-insert locking nuts (2 per U-bolt)
• 8x Phosphate-coated, heat-treated extra-thick washers (2 per U-bolt)

Product Description

The Superlift 11884 is a 4-pack of square U-bolts sized 5/8 in. x 3-1/4 in. x 16 in., complete with locking nuts and heavy-duty washers. The square profile is designed for applications where the axle housing or spring perch has a flat bottom seat - ensuring the bolt registers squarely and delivers even clamping force across the full width of the spring plate. At 16 in. leg length and 5/8 in. rod diameter, these are built for heavy-duty full-size truck axles requiring long U-bolts, such as Dodge Ram HD applications with Dana 70 or Dana 80 rear axles or similar large spring pack configurations.

Built from low alloy, high-strength steel with a 115,000 PSI yield strength and 133,000 PSI tensile strength, these U-bolts meet the demanding clamping loads of lifted suspension setups running lift blocks, add-a-leafs, or replacement spring packs. National Fine Class 2A threads ensure accurate torque-to-clamp-load relationships. The included aircraft-type nylon-insert locking nuts and phosphate-coated extra-thick washers are ready for immediate installation. Made in the USA and backed by Superlift's limited lifetime warranty.