Husqvarna 505435302 Clutch Spring – Genuine OEM Replacement Clutch Spring

Part Number: 505435302
Category: Brushcutter, Clearing Saw & Trimmer Clutch Components
Type: Clutch Spring – Genuine OEM Replacement Clutch Spring

The Husqvarna 505435302 Clutch Spring is a genuine OEM replacement clutch component designed for select Husqvarna brushcutters, clearing saws, and compatible Jonsered handheld equipment. Husqvarna's official genuine-parts catalog identifies 505435302 specifically as a Clutch Spring and documents it across numerous professional brushcutter and clearing-saw models. 

Product Specifications

• Part Number: 505435302
• Manufacturer: Husqvarna
• Product Type: Clutch Spring
• OEM Description: Clutch Spring
• Component Type: Centrifugal Clutch Component
• Function: Controls Clutch Shoe Retraction & Engagement
• Primary Application: Brushcutter / Clearing Saw
• Compatible Brands: Husqvarna / Jonsered
• Installation Location: Engine Clutch Assembly
• Associated Components: Clutch Shoes / Clutch Hub / Clutch Drum / Bearing / Retaining Hardware
• Replacement Type: Direct OEM Replacement
• OEM Status: Genuine Husqvarna OEM Part
• Condition: New
• Quantity: 1 Clutch Spring
• Part Number Reference: 505435302
• Alternate Number Format: 505 43 53-02
• Replaces: 505435301 / 503953801
• UPC: 193028503018
• Approximate Weight: 0.01 lb

OEM-parts references confirm that 505435302 replaces previous clutch spring numbers 505435301 and 503953801. The UPC is documented as 193028503018.

Features & Benefits

• Genuine Husqvarna OEM replacement component
• Factory-designated Clutch Spring
• Designed for compatible centrifugal clutch assemblies
• Helps retain clutch shoes at lower engine speeds
• Supports proper clutch engagement as engine RPM increases
• Helps maintain controlled transfer of engine power
• Supports proper clutch-shoe movement
• Helps maintain the factory clutch operating characteristics
• Designed for high-speed handheld outdoor power equipment
• Suitable for professional brushcutters and clearing saws
• Application-specific OEM fit
• Replacement for worn, stretched, weakened, or broken clutch springs
• Supersedes earlier 505435301
• Direct replacement for equipment requiring 505435302
• Genuine OEM component rather than an unspecified universal clutch spring

Clutch Spring Function

The 505435302 operates within a centrifugal clutch assembly.

At idle or lower engine speeds, the spring helps:

• Hold the clutch shoes inward
• Keep the shoes away from the clutch drum
• Prevent unnecessary cutting-head engagement
• Maintain the intended clutch position

As engine RPM increases:

• Centrifugal force acts on the clutch shoes
• The shoes move outward against spring tension
• The shoes contact the clutch drum
• Engine power is transferred through the drivetrain
• The cutting attachment can rotate

When engine speed decreases, the spring helps pull the clutch shoes back toward their disengaged position.

Centrifugal Clutch Operation

A properly operating clutch is important because handheld cutting equipment is designed so the cutting attachment does not remain fully driven at normal idle.

The clutch assembly generally includes:

• Clutch shoes
• Clutch springs
• Clutch hub
• Clutch drum
• Drum bearing
• Washers
• Retainers
• Mounting hardware

The spring is relatively small, but its tension directly affects how the clutch shoes respond to engine speed.

Documented Husqvarna Applications

Husqvarna's official genuine-parts documentation lists 505435302 for models including:

• Husqvarna 343 F
• Husqvarna 343 FR
• Husqvarna 343 R
• Husqvarna 345 FR
• Husqvarna 345 FX
• Husqvarna 345 FXT
• Husqvarna 345 R
• Husqvarna 345 RX
• Husqvarna 355 FRM
• Husqvarna 355 FX
• Husqvarna 355 FXT
• Husqvarna 355 RX
• Husqvarna 545 FR
• Husqvarna 545 FX
• Husqvarna 545 FX AT
• Husqvarna 545 FXT
• Husqvarna 545 FXT AT
• Husqvarna 545 RX
• Husqvarna 545 RXT
• Husqvarna 545 RXT AT

Husqvarna also lists the spring for compatible BC, CC, FC, and MC-series equipment.

Exact fitment should always be verified using the complete equipment model, serial range, and illustrated parts diagram.

Additional Documented Applications

Husqvarna's genuine-parts catalog also identifies 505435302 for:

• BC2145
• BC2255
• CC2145
• CC2245
• FC2145
• FC2145 S
• FC2145 W
• FC2245
• FC2245 W
• FC2255
• FC2255 W
• MC2255

This broad model coverage reflects the use of the same clutch spring across multiple compatible professional handheld platforms.

Husqvarna 545 RXT AT Clutch Assembly

Current Husqvarna documentation for the 545 RXT AT provides a clear example of how 505435302 is used.

The clutch assembly includes:

• Clutch cover
• Ball bearing
• Circlip
• Clutch drum assembly
• Clutch assembly
• Clutch mounting screws
• 505435302 Clutch Spring

Importantly, Husqvarna specifies a quantity of three 505435302 clutch springs within this particular clutch assembly.

The quantity required can vary by application, so customers should verify their specific parts diagram before ordering.

Replaces 505435301

The current 505435302 supersedes previous Husqvarna clutch spring:

505435301

Parts diagrams for equipment such as the Husqvarna 355 FXT identify 505435301 as a 1.7 mm clutch spring that has been superseded to 505435302.

Additional OEM-parts references identify:

• 503953801
• 505435301

as previous numbers replaced by 505435302.

Common Reasons for Replacement

Replacement of the 505435302 Clutch Spring may be appropriate if the original spring has:

• Broken
• Snapped
• Become stretched
• Lost tension
• Become distorted
• Developed corrosion
• Sustained excessive heat
• Become disconnected from a clutch shoe
• Developed worn attachment points
• Been damaged during clutch service
• Become unable to retract the clutch shoes properly
• Been lost during clutch disassembly

Springs store mechanical energy and can fail when subjected to stress beyond their intended operating range.

Possible Signs of Clutch Spring Problems

A worn or damaged clutch spring may contribute to:

• Cutting attachment moving at idle
• Clutch engaging too early
• Clutch failing to disengage properly
• Irregular clutch engagement
• Excessive clutch vibration
• Rattling from the clutch area
• Clutch shoes remaining partially extended
• Abnormal clutch drum movement
• Poor power transfer
• Increased clutch wear

These symptoms can also result from worn clutch shoes, a damaged clutch drum, incorrect idle speed, bearing problems, or other drivetrain issues.

Cutting Attachment Moving at Idle

If the cutting attachment continues rotating while the engine is at normal idle, inspect the clutch system.

Possible causes can include:

• Broken clutch spring
• Stretched clutch spring
• Worn clutch shoes
• Damaged clutch components
• Excessive engine idle speed
• Binding within the clutch assembly

A clutch spring should not automatically be assumed to be the sole cause without inspecting the complete system.

Clutch Inspection

When replacing 505435302, inspect the surrounding:

• Clutch shoes
• Remaining clutch springs
• Clutch hub
• Clutch drum
• Drum bearing
• Clutch cover
• Retaining ring
• Washers
• Mounting screws
• Drive shaft components

If one spring has failed from fatigue or heat, the remaining springs should also be inspected closely.

Spring Replacement Considerations

On clutch assemblies using multiple springs, spring condition can influence the balance and engagement characteristics of the clutch.

For example, the current Husqvarna 545 RXT AT IPL specifies three 505435302 springs in its clutch assembly.

Therefore:

• Verify how many springs your clutch uses.
• Do not assume one spring completes the clutch assembly.
• Inspect all springs when the clutch is disassembled.
• Verify that each spring is correctly seated.
• Replace damaged clutch shoes or other components separately as necessary.

Installation Considerations

Before replacing the clutch spring:

1. Shut off the engine.
2. Allow the engine and clutch to cool.
3. Disconnect the spark plug.
4. Remove the applicable clutch/drivetrain cover.
5. Access the clutch assembly according to the equipment service procedure.
6. Note the original spring and clutch-shoe orientation.
7. Carefully release spring tension.
8. Inspect the clutch shoes and hub.
9. Install the replacement 505435302 in the correct position.
10. Confirm that the spring is fully seated at both attachment points.
11. Reassemble the clutch and drivetrain components.
12. Verify proper clutch operation before normal use.

Clutch springs are tensioned mechanical components and should be handled carefully during removal and installation.

Important Notes

• Verify compatibility with your exact equipment model, serial number, product number, and production revision before ordering.
• Match part number 505435302 directly with the equipment's OEM illustrated parts diagram.
• Husqvarna's official genuine-parts catalog identifies 505435302 as a Clutch Spring.
• This part is primarily documented for brushcutters and clearing saws, rather than mower-deck clutch systems.
• 505435302 replaces 505435301 and 503953801.
• Previous 505435301 is documented as a 1.7 mm clutch spring on applicable clutch assemblies.
• UPC is 193028503018.
• Do not select a replacement clutch spring solely by approximate length or appearance.
• Clutch springs can differ in wire diameter, overall length, hook configuration, spring rate, tension, and intended engagement characteristics.
• Use 505435302 as the primary fitment reference.
• Do not stretch, shorten, cut, bend, or otherwise modify the replacement spring.
• Do not substitute an arbitrary hardware spring.
• The clutch operates at high rotational speeds and requires correctly specified components.
• Inspect all clutch shoes and springs when servicing the assembly.
• Some applications require multiple 505435302 springs; the 545 RXT AT, for example, specifies three.
• Do not assume multiple springs are included when purchasing one 505435302.
• Check the OEM diagram for the required quantity.
• Inspect the clutch drum for excessive wear, scoring, cracking, or heat damage.
• Inspect the clutch bearing and retainers where applicable.
• Make sure each spring is securely attached before reassembly.
• Verify that clutch shoes retract properly after installation.
• Confirm that the cutting attachment does not remain driven at normal idle.
• If the cutting attachment continues moving at idle after clutch repair, shut down the equipment and diagnose the clutch and engine idle settings before further use.
• Allow hot engine and clutch components to cool before service.
• Disconnect the spark plug before performing clutch repairs.
• Wear appropriate eye protection when handling tensioned springs.
• This listing is for one Husqvarna 505435302 Clutch Spring only unless otherwise specified. Clutch shoes, clutch drum, bearings, hub, additional springs, washers, and mounting hardware are sold separately unless explicitly included.
• Match Husqvarna 505435302 with your equipment's OEM parts diagram and verify the required quantity before ordering to ensure proper fitment.