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Description
4243 740 5001 STIHL HL-KM 0° Gear Head Assembly – Genuine OEM Angle Drive Attachment Part
The STIHL HL-KM 0° Gear Head Assembly (4243 740 5001) is a genuine OEM gearbox and cutting head component designed for the STIHL HL-KM long-reach hedge trimmer KombiTool attachment. This 0-degree fixed-angle gear head provides direct straight-line trimming performance, delivering smooth and consistent blade drive power for professional hedge and shrub maintenance.
The gear head is a critical drivetrain component, transferring rotational power from the drive shaft to the cutter bar system. Over time, internal gears may wear due to heavy commercial use, lack of lubrication, impact damage, or long-term vibration. A failing gear head may cause excessive noise, reduced blade speed, gear slipping, or complete loss of cutting function.
Replacing the gear head assembly with the correct genuine STIHL OEM part restores factory performance, proper blade alignment, and long-term durability without replacing the entire KombiTool attachment.
Manufactured to STIHL factory specifications, this OEM gear head ensures precise fitment, smooth gear engagement, and dependable cutting power under demanding working conditions.
Product Details
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OEM Part Number: 4243 740 5001
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Brand: STIHL (Genuine OEM)
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Part Type: Gear Head / Angle Drive Assembly
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Angle Configuration: 0° Fixed Straight Head
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Application: Power transmission to cutter bar system
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Condition: New Genuine OEM Part
Function
This STIHL HL-KM 0° gear head assembly is designed to:
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Transfer driveline power to the hedge trimmer blade system
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Maintain smooth and consistent cutter bar motion
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Support straight-angle trimming applications
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Replace worn, noisy, or damaged gear drive heads
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Restore safe and reliable hedge trimming performance
⚠️ A worn gear head may cause vibration, noise, or complete blade drive failure.
Verify Fitment (Recommended)
Before ordering, confirm:
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OEM part number 4243 740 5001
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Your attachment is the HL-KM 0° version
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Gear head configuration matches your drive tube assembly
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Your unit matches the models listed below
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Fitment is verified using your STIHL illustrated parts diagram
⚠️ Gear heads are model-specific — always confirm by OEM part number.
Compatibility
This OEM gear head assembly fits select STIHL Kombi hedge trimmer attachments, including:
KombiTool Hedge Trimmer Attachments
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HL-KM 0° Long-Reach Hedge Trimmer Attachment
(Exact fitment depends on production version — always verify using OEM parts diagram.)
Installation Notes
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Disconnect power source before servicing
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Remove cutter bar and drive tube components as required
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Detach worn gear head assembly carefully
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Install new OEM gear head ensuring correct spline engagement
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Reassemble housing and torque fasteners to specification
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Test blade rotation and gearbox performance
⚠️ Gear head replacement should be performed by a qualified technician to ensure proper alignment and safe operation.
Maintenance Tips
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Lubricate gearbox regularly using STIHL-approved grease
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Inspect for vibration or abnormal noise during operation
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Avoid impacts or bending stress on the cutter bar assembly
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Replace worn gear heads promptly to prevent driveline damage
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Always use genuine STIHL OEM parts for best fit and durability

