Komatsu Part BUSHING 427-46-11440

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Product Overview

The 427-46-11440 BUSHING is a genuine Komatsu OEM replacement bushing from the 427 prefix series. Bushings are the controlled-wear components installed at pivot joints throughout your machine — boom connections, arm linkages, bucket pins, cylinder mounts, and track frame pivots all rely on bushings to provide the bearing surface between the hardened steel pin and the structural housing bore. The bushing is deliberately softer than both the pin and the housing, ensuring it wears first and can be replaced economically when the running clearance exceeds the design specification.

Part Number: 427-46-11440 Part Name: BUSHING Part Type: OEM Komatsu Replacement Bushing Availability: In stock

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The Wear Mechanism and Replacement Economics

Bushing wear follows a characteristic progression driven by abrasive contamination. Dirt and grit work past the joint seals, mixing with the grease inside to form a grinding paste. Each oscillation of the pin within the bushing presses this abrasive mixture against the bushing surface, removing microscopic amounts of material. Over thousands of cycles, the bore enlarges and the wall thickness decreases. The wear rate is relatively slow and linear during the early stages because the load is distributed across a broad contact area. But once the clearance grows beyond its design limit, two things happen. First, the loading changes from distributed contact to impact loading as the pin hammers against the bushing with each load reversal. Second, the increased clearance allows the abrasive mixture to flow more freely through the joint rather than being expelled, accelerating the contamination of fresh grease. The wear rate increases dramatically at this point.

The economics are straightforward if caught at the right time. A bushing replaced before impact wear begins costs the bushing itself, a pin (if it shows any wear), seals, fresh grease, and a few hours of shop labor. The same joint left until the bushing completely fails allows the pin to hammer directly against the housing bore, elongating it. That repair requires welding, line boring, and possibly housing replacement — an repair that costs an order of magnitude more than the preventive bushing change would have. Replace the 427-46-11440 when rocking the connected parts reveals movement; when the bore is oval or elongated; when surface cracks, galling, or scoring are visible; when grease leaks past the bushing face; or when the mating pin shows a wear ridge.

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Installation

1. Confirm 427-46-11440 in your Komatsu parts catalog
2. Press or drive out the old bushing using a driver with the correct pilot diameter — protect the housing bore from scoring
3. Clean the housing bore completely — every fragment of the old bushing must be removed
4. Inspect the mating pin — if any wear ridge or surface damage is visible, replace it together with the bushing
5. Press the new bushing to the correct depth — align any grease holes or grooves with the housing
6. Apply assembly grease to the bore before inserting the pin
7. Pump fresh grease through the fitting until clean grease appears at the seals, cycle the joint several times, and re-grease

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Request a Quote

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