VH135052581A Idle Gear Sub Assy

VH135052581A J05E Idle Gear Sub Assy For SK200-8 SK250-8 SK260LC-8 Kobelco Excavator

Product Overview

The VH135052581A J05E Idle Gear Sub Assembly is a key intermediary gear (or set of gears) mounted in the engine’s front gear case or block. It meshes with the crankshaft gear and drives the camshaft gear(s) and other auxiliary components (such as the fuel injection pump gear or oil pump), ensuring they all rotate in precise synchronization. This sub-assembly typically includes the idler gear itself, mounted on a shaft with bearings or bushings. Our replacement unit is manufactured to meet strict OEM tolerances for gear tooth profile, pitch, hardness, and shaft dimensions, ensuring perfect meshing, correct gear lash (clearance), and quiet, efficient power transmission throughout the engine’s operating range.

Key Features & Benefits

• Precision OEM Fit & Timing: A direct replacement for part number VH135052581A, guaranteeing perfect gear alignment, correct tooth engagement, and restoration of factory-specified timing relationships between the crankshaft, camshaft, and fuel pump.

• Eliminates Gear Train Noise & Wear: Replaces worn gears and bearings to eliminate knocking, whining, or grinding noises from the front timing cover, and prevents accelerated wear on all meshing gears in the train.

• Ensures Critical Engine Synchronization: Maintains the exact angular relationship essential for proper valve timing and fuel injection timing, which is critical for engine power, efficiency, and emissions control.

• Prevents Catastrophic Engine Damage: A failed idler gear can cause the timing system to jump teeth or seize, leading to bent valves, piston-to-valve contact, and complete engine destruction.

• Durable, Hardened Construction: Gears are made from high-grade alloy steel, precision-cut and heat-treated (case-hardened) for maximum surface hardness and wear resistance, ensuring a long service life.

• Complete, Ready-to-Install Assembly: Supplied as a sub-assembly with the gear pre-mounted on its shaft with necessary bearings or bushings, simplifying installation and ensuring component compatibility.

Technical Specifications

• Part Number: VH135052581A

• Application: Idle Gear / Idler Gear Sub Assembly (Timing Gear Train)

• Engine Compatibility: J05E Engine Series

• Compatible Models: Kobelco SK200-8, SK250-8, SK260LC-8 Excavators

• Function: Transfers rotation from crankshaft to camshaft and auxiliary components.

Frequently Asked Questions (FAQ)

Q1: What are the symptoms of a failing idler gear assembly (VH135052581A)?
A: Common warning signs include:

• Loud, repetitive knocking or grinding noise from the front of the engine (timing cover area), often varying with engine RPM.

• Increased engine noise overall, specifically a gear whine or chatter.

• Engine performance issues like loss of power or rough running, if wear affects timing accuracy.

• Metal particles found in the engine oil during an oil change, indicating gear or bearing wear.

Q2: Does replacing this gear require an engine teardown or timing procedure?
A: YES, this is a major internal engine repair. Replacing the idler gear assembly requires:

• Removing the front timing cover (and often the radiator and other components for access).

• Locking the engine in a specific timing position (at Top Dead Center for cylinder #1).

• Carefully marking gear relationships or following precise timing marks.

• This is not a simple external repair. It must be performed by a professional diesel technician with the proper tools, manuals, and expertise.

Q3: Is this a single gear or an assembly with a shaft and bearings?
A: The VH135052581A is a sub-assembly, which typically includes the idler gear mounted on its shaft, along with the necessary needle bearings, bushings, or thrust washers. The specific contents should be confirmed with the supplier, but it is more than just a loose gear.

Q4: Should I replace other timing components when replacing the idler gear?
A: It is highly advisable. If the idler gear has failed due to wear, the gears it meshes with (crankshaft gear, camshaft gear(s), fuel pump gear) are also likely worn. For a lasting repair and to prevent quick re-failure, inspect and often replace the complete timing gear set and related tensioners or guides during this service.

Q5: Why is an OEM-spec gear crucial?
A: The VH135052581A is engineered with the exact tooth geometry, heat treatment, and balance. An incorrect gear can have improper hardness (leading to rapid wear), incorrect tooth profile (causing noise and stress), or imbalance (causing vibration), any of which can lead to premature failure and engine damage.

Protect Your Engine’s Internal Heartbeat. Restore Quiet, Precise Timing – Order the VH135052581A Idle Gear Sub Assembly Today!

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Need Help Confirming Compatibility?
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