Final Drive Gear Set 8-97035455-0 8-97320103-0 For ISUZU NPR66 4HF1 Truck

Final drive gear set (ring and pinion) transmits and reduces engine torque to the wheels, providing the correct final drive ratio and reliable power delivery in ISUZU NPR66 4HF1 trucks.

The Final Drive Gear Set (OEM Numbers: 8-97035455-0 / 8-97320103-0 / 8970354550 / 8973201030) is a premium-quality, direct replacement differential gear set designed specifically for ISUZU NPR66 series medium-duty trucks equipped with 4HF1 diesel engines. This final drive gear set - also known as a ring and pinion gear set or crown wheel and pinion - is the core component of the vehicle's rear axle differential.

• OE Quality: Manufactured to strict ISUZU dimensional and material specifications for perfect fit and function
• High-Strength Alloy Steel: Forged and heat-treated for exceptional strength and wear resistance
• Precision-Machined Teeth: Cut and lapped in matched sets for smooth, quiet operation and proper contact pattern
• Correct Gear Ratio: Matched to the vehicle's powertrain for optimal performance and fuel efficiency
• High Torque Capacity: Withstands the high loads of commercial truck drivetrains
• Restores Differential Performance: Eliminates whining, howling, and power loss caused by worn gears
• Direct Replacement: Matches OE gear dimensions and mounting configuration
• Long Service Life: Engineered for heavy-duty commercial truck applications
• Essential for Differential Overhaul: Critical component to replace during axle rebuild or gear ratio change
• Complete Set: Includes matched ring and pinion gears for reliable installation

This final drive gear set is specifically designed for ISUZU medium-duty trucks and commercial vehicles. Common applications include:

• ISUZU NPR66 (Medium-Duty Trucks)
• ISUZU N Series (NK, NP - as applicable)
• ISUZU 4HF1 Engine Specifications:
  • 4-Cylinder, Inline Diesel
  • Displacement: 4.3L
  • Valvetrain: OHV
  • Application: Medium-duty trucks and commercial vehicles

Also compatible with various ISUZU models using the same rear axle and differential configuration.

Professional driveline specialist installation is essential:

1. Ensure vehicle is safely raised - Use appropriate jack stands or a lift to support the rear axle
2. Drain differential oil - Drain the lubricant into a suitable container
3. Remove the propeller shaft - Disconnect the propeller shaft from the differential companion flange
4. Remove the axle shafts - Remove the rear wheels, brake drums, and axle shafts to access the differential
5. Remove the differential carrier - Unbolt and remove the differential carrier assembly from the axle housing
6. Disassemble the differential - Remove the bearing caps, ring gear, pinion shaft, and old gear set
7. Clean and inspect - Clean all components; inspect the carrier, bearings, and housing for wear or damage
8. Install the new pinion gear - Install the new pinion gear with new bearings and crush sleeve or shims; set pinion bearing preload
9. Install the new ring gear - Bolt the new ring gear to the differential case; torque bolts to specification
10. Adjust backlash and contact pattern - Use shims to set proper backlash and verify gear contact pattern using marking compound
11. Reassemble the differential - Install the differential carrier into the axle housing; torque mounting bolts
12. Reinstall axle shafts - Install the axle shafts, brake components, and wheels
13. Reconnect the propeller shaft - Align match marks made during removal; reconnect universal joints and flanges
14. Refill differential oil - Fill with the correct grade and quantity of differential lubricant
15. Road test - Test drive to verify smooth operation, no abnormal noise, and proper power delivery
16. Re-check oil level - After the initial drive, check for leaks and top up differential oil if necessary

• Material Verification: Confirms alloy steel composition and hardness meet ISUZU strength and wear resistance specifications
• Dimensional Inspection: Ring gear and pinion dimensions, tooth count, and mounting dimensions verified within OEM tolerances
• Tooth Contact Pattern Testing: Each set lapped and tested for proper contact pattern and noise characteristics
• Hardness Testing: Gear teeth tested for proper case hardness and core strength
• Backlash Verification: Sample tested to ensure proper backlash when installed with specified shims
• Visual Inspection: 100% checked for cracks, machining defects, or heat treatment flaws
• Packaged Safely: Protected with rust inhibitor and packaged to prevent damage during transit

• Neutral export packing or customized packaging available
• Carton or wooden case for safe transportation
• Fast delivery for stock items
• Shipping by Express Air or Sea