{"product_id":"husqvarna-521557501-spring-genuine-oem-replacement-equipment-spring","title":"Husqvarna 521557501 Spring – Genuine OEM Replacement Equipment Spring","description":"\u003cdiv class=\"\"\u003e\n\u003csection class=\"text-token-text-primary w-full focus:outline-none has-data-writing-block:pointer-events-none [\u0026amp;:has([data-writing-block])\u0026gt;*]:pointer-events-auto R6Vx5W_threadScrollVars scroll-mb-[calc(var(--scroll-root-safe-area-inset-bottom,0px)+var(--thread-response-height))] scroll-mt-(--sticky-padding-top)\" dir=\"auto\"\u003e\u003c\/section\u003e\n\u003cbr\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"\"\u003e\n\u003csection class=\"text-token-text-primary w-full focus:outline-none has-data-writing-block:pointer-events-none [\u0026amp;:has([data-writing-block])\u0026gt;*]:pointer-events-auto R6Vx5W_threadScrollVars scroll-mb-[calc(var(--scroll-root-safe-area-inset-bottom,0px)+var(--thread-response-height))] scroll-mt-[calc(var(--header-height)+min(200px,max(70px,20svh)))]\" dir=\"auto\"\u003e\n\u003cdiv class=\"text-base my-auto mx-auto pb-8 [--thread-content-margin:var(--thread-content-margin-xs,calc(var(--spacing)*4))] @w-sm\/main:[--thread-content-margin:var(--thread-content-margin-sm,calc(var(--spacing)*6))] @w-lg\/main:[--thread-content-margin:var(--thread-content-margin-lg,calc(var(--spacing)*16))] px-(--thread-content-margin)\"\u003e\n\u003cdiv class=\"[--thread-content-max-width:40rem] @w-lg\/main:[--thread-content-max-width:48rem] mx-auto max-w-(--thread-content-max-width) flex-1 group\/turn-messages focus-visible:outline-hidden relative flex w-full min-w-0 flex-col agent-turn\"\u003e\n\u003cdiv class=\"flex max-w-full flex-col gap-4 grow\"\u003e\n\u003cdiv dir=\"auto\" class=\"min-h-8 text-message relative flex w-full flex-col items-end gap-2 text-start break-words whitespace-normal outline-none keyboard-focused:focus-ring [.text-message+\u0026amp;]:mt-1\" tabindex=\"0\"\u003e\n\u003cdiv class=\"flex w-full flex-col gap-1 empty:hidden\"\u003e\n\u003cdiv class=\"markdown prose dark:prose-invert wrap-break-word w-full light markdown-new-styling\"\u003e\n\u003cp\u003e\u003cstrong\u003ePart Number:\u003c\/strong\u003e 521557501\u003cbr\u003e\u003cstrong\u003eCategory:\u003c\/strong\u003e Chainsaw Clutch, Drive \u0026amp; Engine Components\u003cbr\u003e\u003cstrong\u003eType:\u003c\/strong\u003e Clutch Spring – Genuine OEM Replacement Chainsaw Spring\u003c\/p\u003e\n\u003chr\u003e\n\u003cp\u003eThe \u003cstrong\u003eHusqvarna 521557501 Spring\u003c\/strong\u003e is a genuine OEM \u003cstrong\u003eclutch spring\u003c\/strong\u003e designed for select Husqvarna and RedMax chainsaws. Husqvarna’s official T435 illustrated parts list identifies \u003cstrong\u003e521 55 75-01\u003c\/strong\u003e as the \u003cstrong\u003espring used within the clutch assembly\u003c\/strong\u003e, with three springs specified for that particular clutch configuration.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003eProduct Specifications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e 521557501\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer:\u003c\/strong\u003e Husqvarna\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Clutch Spring\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Description:\u003c\/strong\u003e Spring\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAlternate Description:\u003c\/strong\u003e Chainsaw Clutch Spring \/ Clutch Shoe Spring\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eComponent Type:\u003c\/strong\u003e Clutch \/ Drive System Component\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFunction:\u003c\/strong\u003e Provides Tension Between Applicable Clutch Shoes\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSystem:\u003c\/strong\u003e Centrifugal Clutch \/ Chainsaw Drive System\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApplication:\u003c\/strong\u003e Chainsaw\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompatible Brands:\u003c\/strong\u003e Husqvarna \/ RedMax – Model Dependent\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Metal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eComponent Location:\u003c\/strong\u003e Clutch Assembly\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAssociated Components:\u003c\/strong\u003e Clutch Shoes \/ Clutch Assembly \/ Clutch Drum \/ Roller Bearing\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacement Type:\u003c\/strong\u003e Direct OEM Replacement\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Status:\u003c\/strong\u003e Genuine Husqvarna OEM Part\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCondition:\u003c\/strong\u003e New\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuantity:\u003c\/strong\u003e 1 Spring\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Number Reference:\u003c\/strong\u003e 521557501\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAlternate Number Format:\u003c\/strong\u003e 521 55 75-01\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAlternate Reference:\u003c\/strong\u003e 5215575-01\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 705788536290\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eParts references confirm UPC \u003cstrong\u003e705788536290\u003c\/strong\u003e, while Husqvarna’s official documentation uses the formatted number \u003cstrong\u003e521 55 75-01\u003c\/strong\u003e. \u003cspan class=\"contents\"\u003e\u003cspan class=\"\"\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003eFeatures \u0026amp; Benefits\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eGenuine Husqvarna OEM replacement clutch spring\u003c\/li\u003e\n\u003cli\u003eFactory-designated \u003cstrong\u003e521557501 Spring\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eDesigned for compatible chainsaw clutch assemblies\u003c\/li\u003e\n\u003cli\u003eProvides tension between applicable clutch shoes\u003c\/li\u003e\n\u003cli\u003eSupports proper centrifugal clutch operation\u003c\/li\u003e\n\u003cli\u003eHelps keep clutch shoes retracted at lower engine speeds\u003c\/li\u003e\n\u003cli\u003eAllows clutch shoes to engage as engine speed increases\u003c\/li\u003e\n\u003cli\u003eSupports proper transfer of engine power to the cutting system\u003c\/li\u003e\n\u003cli\u003eHelps maintain the factory clutch engagement characteristics\u003c\/li\u003e\n\u003cli\u003eMetal construction\u003c\/li\u003e\n\u003cli\u003eManufactured for application-specific fit\u003c\/li\u003e\n\u003cli\u003eDesigned to work with compatible OEM clutch components\u003c\/li\u003e\n\u003cli\u003eSuitable for chainsaw clutch repair and maintenance\u003c\/li\u003e\n\u003cli\u003eIdeal replacement for stretched, weakened, distorted, or broken springs\u003c\/li\u003e\n\u003cli\u003eDirect replacement for equipment requiring \u003cstrong\u003e521557501\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eGenuine OEM component rather than an unspecified universal clutch spring\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch2\u003eDocumented Applications\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eHusqvarna 521557501 Clutch Spring\u003c\/strong\u003e is documented for select chainsaws including:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eHusqvarna 439\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eHusqvarna T435\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eRedMax G3200\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eRedMax G3200EZ\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eRedMax GZ3500T\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eRedMax GZ360\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003eSelect additional Husqvarna-produced equipment requiring \u003cstrong\u003e521557501\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003ePartSelect specifically lists these Husqvarna and RedMax chainsaw models for \u003cstrong\u003e521557501\u003c\/strong\u003e. \u003cspan class=\"contents\"\u003e\u003cspan class=\"\"\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eL\u0026amp;S Engineers independently lists the spring for the \u003cstrong\u003eHusqvarna 439 and T435\u003c\/strong\u003e, while Husqvarna’s official T435 parts documentation confirms its position within the clutch and oil-pump assembly. \u003cspan class=\"contents\"\u003e\u003cspan class=\"\"\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eExact compatibility should still be verified using the complete model, product number, serial number, and production revision before ordering.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003eClutch Spring Function\u003c\/h2\u003e\n\u003cp\u003eChainsaws commonly use a centrifugal clutch to automatically engage the cutting chain as engine speed increases.\u003c\/p\u003e\n\u003cp\u003eWithin the applicable assembly, the \u003cstrong\u003e521557501 Clutch Spring\u003c\/strong\u003e helps:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eHold the clutch shoes inward at low engine speed\u003c\/li\u003e\n\u003cli\u003eMaintain tension between the clutch shoes\u003c\/li\u003e\n\u003cli\u003eControl movement of the clutch shoes\u003c\/li\u003e\n\u003cli\u003eAllow centrifugal force to move the shoes outward as RPM increases\u003c\/li\u003e\n\u003cli\u003eSupport engagement with the clutch drum\u003c\/li\u003e\n\u003cli\u003eHelp disengage the clutch when engine speed decreases\u003c\/li\u003e\n\u003cli\u003eMaintain the intended clutch operating characteristics\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eWhen the spring is functioning correctly, the clutch should remain disengaged at the appropriate low engine speed and engage as engine speed rises.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003eHusqvarna T435 Clutch Assembly\u003c\/h2\u003e\n\u003cp\u003eHusqvarna’s official T435 illustrated parts list identifies the following components within the clutch and oil-pump section:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e521557401\u003c\/strong\u003e – Clutch Assembly\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e521557501\u003c\/strong\u003e – Spring\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e521779401\u003c\/strong\u003e – Plate\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e523082601\u003c\/strong\u003e – Clutch Drum\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e520967301\u003c\/strong\u003e – Roller Bearing\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThe official diagram specifies a \u003cstrong\u003equantity of three 521557501 springs\u003c\/strong\u003e within the applicable T435 clutch assembly. \u003cspan class=\"contents\"\u003e\u003cspan class=\"\"\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eThis listing, however, should be treated as \u003cstrong\u003eone individual spring\u003c\/strong\u003e unless the seller explicitly states that multiple springs are included.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003eCommon Reasons for Replacement\u003c\/h2\u003e\n\u003cp\u003eReplacement of the \u003cstrong\u003e521557501 Clutch Spring\u003c\/strong\u003e may be appropriate if the original spring has:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eBroken\u003c\/li\u003e\n\u003cli\u003eSnapped\u003c\/li\u003e\n\u003cli\u003eStretched\u003c\/li\u003e\n\u003cli\u003eBecome weakened\u003c\/li\u003e\n\u003cli\u003eLost tension\u003c\/li\u003e\n\u003cli\u003eBecome distorted\u003c\/li\u003e\n\u003cli\u003eSustained heat damage\u003c\/li\u003e\n\u003cli\u003eDeveloped corrosion\u003c\/li\u003e\n\u003cli\u003eBecome damaged during clutch removal\u003c\/li\u003e\n\u003cli\u003eBecome unable to properly retract the clutch shoe\u003c\/li\u003e\n\u003cli\u003eDeveloped excessive wear at its attachment points\u003c\/li\u003e\n\u003cli\u003eBeen lost during clutch service\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eA failed clutch spring can affect how the clutch shoes engage or disengage from the clutch drum.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003ePossible Signs of Clutch Spring Problems\u003c\/h2\u003e\n\u003cp\u003eDepending on the chainsaw and condition of the clutch assembly, a damaged or weakened spring may contribute to:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eChain movement at idle\u003c\/li\u003e\n\u003cli\u003eAbnormal clutch engagement\u003c\/li\u003e\n\u003cli\u003eClutch engaging too early\u003c\/li\u003e\n\u003cli\u003eClutch shoes failing to retract correctly\u003c\/li\u003e\n\u003cli\u003eIrregular engagement\u003c\/li\u003e\n\u003cli\u003eExcessive clutch vibration\u003c\/li\u003e\n\u003cli\u003eAbnormal noise from the clutch area\u003c\/li\u003e\n\u003cli\u003eVisible loose or damaged clutch shoes\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThese symptoms can also result from incorrect idle adjustment, clutch-shoe wear, clutch-drum damage, or other drive-system problems, so the complete clutch system should be inspected.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003eClutch System Inspection\u003c\/h2\u003e\n\u003cp\u003eWhen replacing the spring, inspect related components including:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eClutch shoes\u003c\/li\u003e\n\u003cli\u003eComplete clutch assembly\u003c\/li\u003e\n\u003cli\u003eClutch drum\u003c\/li\u003e\n\u003cli\u003eRoller bearing\u003c\/li\u003e\n\u003cli\u003eClutch plate\u003c\/li\u003e\n\u003cli\u003eDrive sprocket\u003c\/li\u003e\n\u003cli\u003eCrankshaft\u003c\/li\u003e\n\u003cli\u003eChain brake components\u003c\/li\u003e\n\u003cli\u003eOil pump drive components\u003c\/li\u003e\n\u003cli\u003eMounting and retaining hardware\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eA new spring should not be installed onto severely worn, cracked, distorted, or otherwise damaged clutch shoes.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003eImportant Notes\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eVerify compatibility with your exact chainsaw model, product number, serial number, and production revision before ordering.\u003c\/li\u003e\n\u003cli\u003eMatch \u003cstrong\u003epart number 521557501\u003c\/strong\u003e directly with your equipment's illustrated parts diagram or OEM documentation.\u003c\/li\u003e\n\u003cli\u003eThe alternate formatted part number is \u003cstrong\u003e521 55 75-01\u003c\/strong\u003e. \u003cspan class=\"contents\"\u003e\u003cspan class=\"\"\u003e\u003c\/span\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e5215575-01\u003c\/strong\u003e is another documented formatting of the same reference. \u003cspan class=\"contents\"\u003e\u003cspan class=\"\"\u003e\u003c\/span\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003eAlthough the generic OEM description may simply state \u003cstrong\u003e“Spring,” 521557501 is specifically documented as a clutch spring\u003c\/strong\u003e on compatible chainsaws. \u003cspan class=\"contents\"\u003e\u003cspan class=\"\"\u003e\u003c\/span\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003eThis is a \u003cstrong\u003eclutch spring\u003c\/strong\u003e, not a recoil starter spring, chain-tensioner spring, anti-vibration spring, or general-purpose equipment spring.\u003c\/li\u003e\n\u003cli\u003eDo not select a replacement spring based solely on approximate size or appearance.\u003c\/li\u003e\n\u003cli\u003eClutch springs can differ significantly in length, wire diameter, hook configuration, tension, and operating characteristics.\u003c\/li\u003e\n\u003cli\u003ePartSelect identifies the spring as a metal component used in the clutch assembly to connect the clutch shoes. \u003cspan class=\"contents\"\u003e\u003cspan class=\"\"\u003e\u003c\/span\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003eHusqvarna’s T435 diagram specifies \u003cstrong\u003ethree springs per clutch assembly\u003c\/strong\u003e, but the replacement spring itself is sold individually by multiple parts suppliers. \u003cspan class=\"contents\"\u003e\u003cspan class=\"\"\u003e\u003c\/span\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003eIf replacing one failed spring in a multi-spring clutch, inspect the remaining springs for similar wear or deterioration.\u003c\/li\u003e\n\u003cli\u003eDo not assume that three springs, the clutch shoes, clutch drum, bearing, plate, or complete clutch assembly are included.\u003c\/li\u003e\n\u003cli\u003eInspect the clutch shoes for cracks, glazing, excessive wear, heat damage, or distortion.\u003c\/li\u003e\n\u003cli\u003eInspect the spring attachment points for wear or damage.\u003c\/li\u003e\n\u003cli\u003eCheck the clutch drum for excessive wear, scoring, overheating, cracking, or distortion.\u003c\/li\u003e\n\u003cli\u003eInspect the clutch drum bearing and replace it separately if it feels rough, loose, or damaged.\u003c\/li\u003e\n\u003cli\u003eIf the chain moves excessively at idle, verify correct engine idle speed in addition to inspecting the clutch.\u003c\/li\u003e\n\u003cli\u003eA carburetor or idle-adjustment problem can cause the clutch to engage even when the clutch components themselves are serviceable.\u003c\/li\u003e\n\u003cli\u003eClutch components can become hot during operation. Allow the chainsaw to cool before beginning service.\u003c\/li\u003e\n\u003cli\u003eSprings can release stored tension during removal and installation. Use appropriate tools and eye protection.\u003c\/li\u003e\n\u003cli\u003ePartSelect notes that pliers and an Allen wrench may be required for replacement on applicable equipment. \u003cspan class=\"contents\"\u003e\u003cspan class=\"\"\u003e\u003c\/span\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003eInstall \u003cstrong\u003e521557501\u003c\/strong\u003e in the same position and orientation as the original spring.\u003c\/li\u003e\n\u003cli\u003eMake sure each end of the spring is securely seated in its applicable clutch-shoe attachment point.\u003c\/li\u003e\n\u003cli\u003eAfter installation, verify that the clutch shoes move and retract correctly.\u003c\/li\u003e\n\u003cli\u003eConfirm that the clutch assembly rotates and operates without binding.\u003c\/li\u003e\n\u003cli\u003eReinstall the clutch drum and associated components according to the manufacturer's service procedure.\u003c\/li\u003e\n\u003cli\u003eVerify proper chain operation before returning the chainsaw to service.\u003c\/li\u003e\n\u003cli\u003eShut off the chainsaw, engage the chain brake, allow the engine to cool, and disconnect the spark plug before servicing the clutch.\u003c\/li\u003e\n\u003cli\u003eThis listing is for \u003cstrong\u003eone Husqvarna 521557501 Clutch Spring only\u003c\/strong\u003e unless otherwise specified. Complete clutch assemblies, clutch drums, bearings, plates, sprockets, and other drive components are sold separately unless explicitly included.\u003c\/li\u003e\n\u003cli\u003eMatch \u003cstrong\u003epart number 521557501\u003c\/strong\u003e with your equipment's illustrated parts diagram or OEM documentation before ordering to ensure proper fitment.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/section\u003e\n\u003c\/div\u003e","brand":"Husqvarna","offers":[{"title":"Default Title","offer_id":53746734694763,"sku":"521557501","price":7.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0917\/9201\/5723\/files\/521557501.jpg?v=1787237075","url":"https:\/\/generalsprayers.com\/products\/husqvarna-521557501-spring-genuine-oem-replacement-equipment-spring","provider":"GeneralSprayers","version":"1.0","type":"link"}