ISUZU Timing Cover 8-98057151-0 8980571510 for NPR NQR 700P 4HK1 — OEM Standard Metal Timing Gear Case Cover Verified Fit

The Timing Cover with OEM numbers 8-98057151-0 / 8980571510 is a verified direct-fit replacement for ISUZU NPR, NQR, and NPR 700P trucks equipped with the 4HK1 diesel engine. This timing cover (Timing Cover / Idler Cover Assembly) is installed at the front of the engine, covering the timing gears, chain, or belt area. Together with a gasket, it forms a sealed cavity that prevents external dust, debris, and moisture from entering the timing system while retaining engine oil inside, ensuring the timing mechanism operates in a clean, lubricated environment.

Manufactured from metal material, this timing cover offers good structural rigidity and heat resistance, capable of withstanding the high-temperature and vibration conditions within the engine bay. Produced to OEM standard dimensions with mounting holes that precisely match the original, it allows direct replacement of the original timing cover without modifying the mounting surface or requiring machining.

• Real Specification Data: Material: Metal. Reference dimensions approximately 36 × 32 × 5.5 cm to 38.5 × 32 × 6 cm (supplier records vary). Net weight reference 2.2 kg (some suppliers list approximately 5 kg). Fig.No.-Key No 020-268. HS Code 840999100 (supplier classification reference).
• Proven Durability: Supplier holds ISO/TS16949 certification. Brand BZLP / IZUMI. MOQ 1–5 pcs. Delivery time 5–8 working days. Payment terms T/T, Western Union.
• Fitment Confirmed: Standard mounting dimensions, direct replacement design. Covers ISUZU NPR series / NQR series / NPR 700P series, compatible with 4HK1 diesel engine (some listings also note 4HE1 compatibility).
• OEM Cross-Reference Verified: Replaces ISUZU OEM numbers 8-98039931-1 / 8980399311, 8-98039-932-1 / 8980399321, 1002311-P301, 8971489371, 8971489381, etc. Some suppliers list the new part number as 8980399311.

When the timing cover exhibits the following conditions, timely inspection and replacement are required:

1. Oil seepage around the timing cover: Deformed cover, damaged sealing surface, or loose mounting bolts allow oil to seep from the cover-to-block mating surface, with oil stains visible on the lower front of the engine.
2. Abnormal noise from the timing system (due to external contamination): Cracks or seal failure allow dust and debris to enter the timing cavity, accelerating timing chain/gear wear and producing abnormal noise during operation.
3. Cracks or breakage on the timing cover body: External impact, thermal stress, or casting defects cause the cover to crack, not only losing sealing function but also exposing the timing system to contamination.
4. Deformed mounting surface causing poor sealing: Prolonged high temperature or improper disassembly/assembly warps the mounting surface, preventing effective sealing even with a new gasket.
5. Stripped or cracked bolt holes on the timing cover: Damaged threads or cracks around the bolt holes prevent reliable cover fastening, leading to seal failure and cover looseness.

1. Clean mating surface: Thoroughly clean the timing cover mounting surface and block front mating surface, removing old gasket residue, oil, and rust. Use a plastic scraper to avoid damaging aluminum sealing surfaces.
2. Inspect related components: Check timing chain/gear/belt wear and crankshaft front oil seal condition; replace if necessary.
3. Install new gasket: Align the new timing cover gasket with the dowel pins or mounting holes, confirming correct orientation (if marked).
4. Install timing cover: Reinstall the timing cover, hand-threading all fixing bolts first, then tightening to the specified torque and sequence (typically from center outward in a cross pattern) in steps.
5. Check crankshaft front oil seal: If the timing cover incorporates a crankshaft front oil seal seat, confirm the seal is correctly installed and the lip is lubricated.
6. Fill oil and test: Fill with the specified amount of engine oil. Start the engine and idle, checking the timing cover mating surface and crankshaft front seal for leakage.
7. Road test and recheck: Perform a short road test, recheck for oil leakage, and confirm no abnormal noise from the timing system.

• Every 20,000 km or 12 months: Check around the timing cover for oil seepage and mounting bolt tightness.
• Every 50,000 km: In conjunction with timing system inspection (chain/belt), recheck timing cover sealing condition.
• When timing cover oil seepage or abnormal noise is detected: Inspect the cover sealing surface and timing system promptly; replace the timing cover and gasket if necessary.