ISUZU CXZ81 10PE1 High-Strength Alloy Steel Rear Spring U-Bolt Set with Anti-Corrosion Coating and M27 Rolled Thread

Rear Spring U-Bolt Set 1-87870392-1 1878703921 for ISUZU CXZ81 10PE1 CYZ51K — Verified OEM Fit for Heavy-Duty Rear Leaf Spring Clamping System

This U-bolt set is a critical clamping component of the rear leaf spring suspension system, responsible for securing the rear leaf spring pack to the drive axle housing and maintaining proper suspension geometry under heavy loads.

The rear spring U-bolt set serves as the primary clamping mechanism that binds the rear leaf spring assembly to the drive axle. It provides the force required to clamp the leaf spring and axle together, preventing lateral and longitudinal movement during vehicle operation.

ISUZU genuine U-bolt sets are manufactured from high-strength alloy steel with rolled threads for superior fatigue resistance, ensuring consistent clamping force throughout the service life of the suspension system.

• Visible corrosion or pitting on U-bolt surface — rust penetration reduces the effective cross-sectional area and load-carrying capacity
• Loose or elongated U-bolt threads — thread deformation from over-torque or fatigue prevents proper nut tightening and torque retention
• Leaf spring misalignment or shifting — the spring pack moves out of position relative to the axle, causing rear axle misalignment or abnormal tire wear
• Clunking or knocking noise from rear suspension — loose U-bolts allow the spring pack to shift during acceleration, braking, or cornering
• Deformed or stretched U-bolt legs — indicates the U-bolt has been stressed beyond its elastic limit, requiring immediate replacement

IMPORTANT: Suspension system service must be performed by a qualified technician. Always support the vehicle on a hoist and relieve spring tension before loosening U-bolts. Never reuse old U-bolts.

1. Preparation: Raise the vehicle on a hoist. Support the rear axle independently to relieve tension on the leaf springs.
2. Removal: Remove the U-bolt nuts, washers, and anchor plate. Remove the old U-bolts.
3. Inspection: Inspect the leaf spring pack and axle housing seat for wear, cracks, or deformation. Replace any damaged components.
4. Installation: Install new U-bolts over the leaf spring and axle housing. Install the anchor plate, washers, and nuts.
5. Torque Sequence: Tighten U-bolt nuts in a diagonal sequence. First stage: 25 N·m (18 lb ft). Second stage: 110 N·m (81 lb ft).
6. Final Check: Verify the spring is properly seated and centered on the axle.
7. Re-torque: Re-torque U-bolt nuts after the first 100 km of driving.