ISUZU NPR 4HE1 4.8L Diesel Hypoid Spiral Bevel Final Drive Gear Set - Case-Hardened Alloy Steel Direct OEM Replacement

A precision-engineered hypoid ring and pinion gear set that provides the final torque multiplication and speed reduction from the transmission to the rear wheels, ensuring optimal power delivery for Isuzu 4.8L 4HE1 engines.

• OE Quality: Manufactured to strict ISUZU OEM dimensional, material and performance standards for perfect direct-fit replacement
• Matched Set: Each pinion and ring gear are lapped together as a set and etched with matching numbers for correct tooth contact and quiet operation
• Precision Ground Hypoid Design: Provides smooth, efficient torque transfer with higher load capacity and quieter operation
• Case-Hardened Alloy Steel: Forged from premium SAE 8620/4320 alloy steel, heat-treated for exceptional core toughness and surface hardness
• Multiple Ratio Options: Available in standard ratios including 7:39 (5.57), 6:37 (6.17), 8:39 (4.88) and 6:41 (6.83)
• Direct Replacement for GM Variants: Fully compatible with Chevrolet W-Series and GMC Forward trucks
• 12-Month Warranty: Backed by manufacturer batch traceability and comprehensive warranty
• ISO 9001:2015 / IATF 16949 Certified: Manufacturing facility meets international automotive quality standards

ISUZU Trucks (Primary Fitment):

• ISUZU NPR/NPR-HD (1999-2004) - primary fitment
• ISUZU NQR (1999-2004) - compatible heavy-duty chassis
• ISUZU ELF (N-Series) (1999-2004) - Japanese domestic and export variants
• ISUZU NPR58/NPR59/NPR60/NPR66 (1999-2004) - cross-compatible where 4HE1 engine was fitted

Chevrolet / GMC Models (Cross-Compatible):

• Chevrolet W3500/W4500/W5500 Tiltmaster (1999-2004)
• GMC W3500/W4500/W5500 Forward (1999-2004)

Engine Compatibility:

• 4HE1 4.8L - Naturally aspirated/turbocharged (primary fitment)
• 4HE1-TC 4.8L - Turbocharged & intercooled (1999-2001 NPR, NQR)
• 4HE1-XS 4.8L - Heavy-duty variant

• Gear whine/howl on acceleration - Worn pinion or ring gear teeth
• Growl/rumble on deceleration - Worn ring gear teeth or damaged pinion shaft bearing surfaces
• Clunk/thump when shifting - Excessive gear backlash due to worn thrust surfaces
• Metal particles in differential oil - Advanced ring and pinion wear or scoring
• Complete tooth fracture - Can cause rear axle lock-up and vehicle skidding

• Material Verification: Forged alloy steel composition verified via spectrographic analysis
• Dimensional Accuracy: Verified against OE blueprints using CMM equipment
• Tooth Profile Inspection: Gear teeth inspected using dedicated gear checking equipment
• Hardness Testing: Induction case depth and surface hardness verified via Rockwell testing
• Lapping & Contact Pattern Check: Each matched set tested for proper tooth bearing
• Runout Measurement: Radial runout measured to ensure concentric mounting
• Visual Inspection: 100% inspected for grinding burns, surface cracks, or chip marks

• Individual Packaging: Anti-corrosion oil-coated, sealed in moisture-barrier VCI bag with OE-style labeling
• Wholesale/Bulk Orders: Available in case packs (5, 10, 20, 50 sets) with pallet pricing for volume orders
• Customization: Neutral or private-label retail packaging available for volume wholesale orders
• Fast Shipping: Ready stock for immediate dispatch worldwide via express courier or sea freight