{"product_id":"deck-belt-m154621","title":"M154621 Deck Belt for John Deere X300 X304 X310 Z245 | 146-1\/4 Inch","description":"\u003ch2\u003eOverview\u003c\/h2\u003e\n\u003cp\u003eThis aftermarket \u003cstrong\u003eM154621 mower deck belt\u003c\/strong\u003e fits select John Deere X300, X304, X310, and early-production Z245 mower-deck configurations using the M154621 belt path.\u003c\/p\u003e\n\u003cp\u003eThe supplier lists this replacement at approximately \u003cstrong\u003e1\/2 inch wide by 146-1\/4 inches long\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eImportant:\u003c\/strong\u003e M154621 is not the correct belt for every deck installed on these mower families. Match the original belt number before ordering.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eAftermarket mower-deck drive belt\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePrimary OEM Number:\u003c\/strong\u003e M154621\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuantity Included:\u003c\/strong\u003e One deck belt\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSupplier-Listed Length:\u003c\/strong\u003e 146-1\/4 inches \/ 3714.7 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSupplier-Listed Width:\u003c\/strong\u003e 1\/2 inch\u003cstrong\u003e\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBelt Section:\u003c\/strong\u003e HA-section mower-drive belt path\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Polyester-reinforced aftermarket construction\u003c\/li\u003e\n\u003cli\u003eDesigned for select John Deere mower-deck drive systems\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch2\u003eReplaces These Belt Numbers\u003c\/h2\u003e\n\u003ch3\u003eJohn Deere Part Numbers\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eM154621\u003c\/li\u003e\n\u003cli\u003eA-M154621\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSupplier Reference\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eBT451-HD-MDR\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSearch-Friendly Number Formats\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eM154621\u003c\/li\u003e\n\u003cli\u003eAM154621\u003c\/li\u003e\n\u003cli\u003e154621\u003c\/li\u003e\n\u003cli\u003eBT451HDMDR\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch2\u003eBelt Specifications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eComponent:\u003c\/strong\u003e Mower-deck drive belt\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEffective Length:\u003c\/strong\u003e 3714.6 mm \/ 146.24 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNominal Supplier Length:\u003c\/strong\u003e 146-1\/4 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSupplier Nominal Width:\u003c\/strong\u003e 1\/2 inch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBelt Section:\u003c\/strong\u003e HA section\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuantity:\u003c\/strong\u003e One belt\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eBelt measurements can vary slightly depending on whether a catalog lists effective length, outside circumference, inside circumference, or nominal dimensions. Use the original \u003cstrong\u003eM154621\u003c\/strong\u003e part number as the primary fitment check.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003eCompatible John Deere Model Paths\u003c\/h2\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eModel\u003c\/th\u003e\n\u003cth\u003eCommon Deck Path\u003c\/th\u003e\n\u003cth\u003eFitment Note\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eJohn Deere X300\u003c\/td\u003e\n\u003ctd\u003eSelect 42-inch mower decks\u003c\/td\u003e\n\u003ctd\u003eUsed on certain X300 deck configurations. Confirm the original M154621 number because other X300 decks use different belts.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eJohn Deere X304\u003c\/td\u003e\n\u003ctd\u003e42X mower deck\u003c\/td\u003e\n\u003ctd\u003ePrimary deck-belt path for select X304 All-Wheel-Steer tractors equipped with the compatible 42X deck.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eJohn Deere X310\u003c\/td\u003e\n\u003ctd\u003eSelect 42-inch mower decks\u003c\/td\u003e\n\u003ctd\u003eUsed on certain X310 deck configurations. Check the deck identification and original belt number.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eJohn Deere Z245 EZtrak\u003c\/td\u003e\n\u003ctd\u003e48-inch mower deck\u003c\/td\u003e\n\u003ctd\u003eUsed on early-production Z245 models through serial number 100000. Later models use M158130.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003eModel names are provided as fitment clues only. John Deere produced multiple mower-deck and serial-number configurations within these model families.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003eJohn Deere X300 Fitment Note\u003c\/h2\u003e\n\u003cp\u003eThe M154621 belt appears on selected John Deere X300 mower-deck configurations. Other X300 decks may use belt numbers such as M154601, M155525, M154897, or another model-specific path.\u003c\/p\u003e\n\u003cp\u003eConfirm the original deck identification, belt number, tension-arm layout, and pulley routing before ordering for an X300.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003eJohn Deere X304 Fitment Note\u003c\/h2\u003e\n\u003cp\u003eThe M154621 is a primary mower-deck belt path for the John Deere X304 equipped with the compatible \u003cstrong\u003e42X mower deck\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp\u003eThe X304 may also be found with a dedicated 42M mulching-deck configuration using a different belt. Do not select M154621 solely from the X304 model name.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003eJohn Deere X310 Fitment Note\u003c\/h2\u003e\n\u003cp\u003eThe M154621 belt is used on selected John Deere X310 42-inch mower-deck configurations.\u003c\/p\u003e\n\u003cp\u003eThe X310 uses separate deck-drive and tractor-traction belt systems. Confirm that M154621 is the mower-deck belt being replaced rather than the traction-drive belt.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003eJohn Deere Z245 Serial-Number Note\u003c\/h2\u003e\n\u003cp\u003eThe John Deere Z245 with a 48-inch deck uses two different mower-belt paths based on serial number:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eM154621:\u003c\/strong\u003e Z245 serial numbers through 100000\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM158130:\u003c\/strong\u003e Z245 serial numbers 100001 and higher\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eLocate the mower identification label and confirm the serial number before ordering this belt for a Z245.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003eBefore Ordering\u003c\/h2\u003e\n\u003cp\u003eConfirm all of the following before ordering:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eThe original mower-deck belt number is \u003cstrong\u003eM154621\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003eThe mower is a compatible John Deere X300, X304, X310, or early Z245 configuration.\u003c\/li\u003e\n\u003cli\u003eThe replacement is for the mower-deck drive system rather than the tractor traction-drive system.\u003c\/li\u003e\n\u003cli\u003eThe original belt follows an approximately 146-1\/4-inch effective-length path.\u003c\/li\u003e\n\u003cli\u003eThe original belt width and pulley grooves match the M154621 configuration.\u003c\/li\u003e\n\u003cli\u003eThe deck shell, tension arm, idler pulleys, spindle pulleys, and belt guides match the original routing.\u003c\/li\u003e\n\u003cli\u003eFor a Z245, the mower serial number is 100000 or lower.\u003c\/li\u003e\n\u003cli\u003eThe original belt number remains visible or is confirmed through a model-specific John Deere diagram.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eDo not install the belt until the part number, deck type, dimensions, and pulley routing have been confirmed.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003eCommon Symptoms of a Worn Deck Belt\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eMower blades turn slowly under cutting load\u003c\/li\u003e\n\u003cli\u003eBelt squeals when the PTO clutch engages\u003c\/li\u003e\n\u003cli\u003eBelt repeatedly jumps off a spindle or idler pulley\u003c\/li\u003e\n\u003cli\u003eVisible cracking, glazing, fraying, or burned belt surfaces\u003c\/li\u003e\n\u003cli\u003eLoose belt tension despite the tension arm being engaged\u003c\/li\u003e\n\u003cli\u003eReduced grass-discharge or bagging performance\u003c\/li\u003e\n\u003cli\u003eBurning-rubber smell near the mower deck\u003c\/li\u003e\n\u003cli\u003ePTO clutch engages but the mower blades do not begin turning\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003ePark the mower on a level surface and remove the ignition key.\u003c\/li\u003e\n\u003cli\u003eDisconnect the spark-plug leads before working near the mower deck.\u003c\/li\u003e\n\u003cli\u003ePhotograph or sketch the original belt routing before removal.\u003c\/li\u003e\n\u003cli\u003eInspect the idler pulleys, spindle pulleys, bearings, belt guides, and tension spring.\u003c\/li\u003e\n\u003cli\u003eReplace seized pulleys or damaged tension components before installing the new belt.\u003c\/li\u003e\n\u003cli\u003eConfirm the belt is seated completely inside every pulley groove.\u003c\/li\u003e\n\u003cli\u003eCheck that the flat and V-shaped sides of the belt contact the correct pulleys.\u003c\/li\u003e\n\u003cli\u003eRotate the mower-deck pulley system manually before starting the engine.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch2\u003eShipping Note\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eQuick-ship item:\u003c\/strong\u003e This product may ship from a supplier fulfillment facility to speed up delivery. PTO Direct USA remains your seller of record and support contact for the order.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003eFAQ\u003c\/h2\u003e\n\u003ch3\u003eWhat does the M154621 deck belt fit?\u003c\/h3\u003e\n\u003cp\u003eM154621 is used on select John Deere X300, X304, X310, and early-production Z245 mower-deck configurations. Confirm the original belt number and deck setup before ordering.\u003c\/p\u003e\n\u003ch3\u003eHow long is the John Deere M154621 belt?\u003c\/h3\u003e\n\u003cp\u003eJohn Deere lists an effective length of approximately \u003cstrong\u003e146.24 inches\u003c\/strong\u003e, or 3714.6 mm. The aftermarket supplier lists the belt nominally at 146-1\/4 inches.\u003c\/p\u003e\n\u003ch3\u003eHow wide is the M154621 belt?\u003c\/h3\u003e\n\u003cp\u003eJohn Deere lists the belt width at \u003cstrong\u003e14.21 mm\u003c\/strong\u003e, approximately 0.559 inch. The aftermarket supplier describes the replacement nominally as a 1\/2-inch belt.\u003c\/p\u003e\n\u003ch3\u003eHow thick is the M154621 belt?\u003c\/h3\u003e\n\u003cp\u003eJohn Deere lists the belt thickness at approximately \u003cstrong\u003e11.4 mm\u003c\/strong\u003e, or 0.449 inch.\u003c\/p\u003e\n\u003ch3\u003eDoes M154621 fit the John Deere X300?\u003c\/h3\u003e\n\u003cp\u003eIt fits selected X300 mower-deck configurations using the M154621 belt path. Not every X300 deck uses this number, so confirm the original belt and deck identification.\u003c\/p\u003e\n\u003ch3\u003eDoes M154621 fit the John Deere X304?\u003c\/h3\u003e\n\u003cp\u003eIt fits select X304 tractors equipped with the compatible 42X mower deck. Dedicated mulching-deck configurations can use a different belt.\u003c\/p\u003e\n\u003ch3\u003eDoes M154621 fit the John Deere X310?\u003c\/h3\u003e\n\u003cp\u003eIt fits selected X310 42-inch deck configurations. Confirm the original belt number and make sure you are replacing the mower-deck belt rather than the tractor traction belt.\u003c\/p\u003e\n\u003ch3\u003eDoes M154621 fit the John Deere Z245?\u003c\/h3\u003e\n\u003cp\u003eIt fits Z245 mowers with 48-inch decks through serial number 100000. Z245 serial numbers 100001 and higher use the M158130 deck-belt path.\u003c\/p\u003e\n\u003ch3\u003eIs M154621 the same as M158130?\u003c\/h3\u003e\n\u003cp\u003eNo. They are separate Z245 serial-number belt paths. Early Z245 models use M154621, while later models use M158130.\u003c\/p\u003e\n\u003ch3\u003eIs M154621 a traction-drive belt?\u003c\/h3\u003e\n\u003cp\u003eNo. This listing is for a mower-deck drive belt. The X300, X304, and X310 tractors use separate traction-drive belts to move the tractor.\u003c\/p\u003e\n\u003ch3\u003eCan I order this belt using the mower model alone?\u003c\/h3\u003e\n\u003cp\u003eNo. Confirm the original belt number, deck type, serial number when applicable, and pulley routing before ordering.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003eRelated John Deere Parts and Guides\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/products\/pto-clutch-am141536\"\u003eAM141536 PTO Clutch Replacement\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/spindle-assembly-am136733\"\u003eAM136733 \/ AM137483 Spindle Assembly\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/mower-blades-am137328\"\u003eJohn Deere 42-Inch Gator-Style Mower Blades\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/blogs\/john-deere-quick-reference\/john-deere-x304\"\u003eJohn Deere X304 Quick Reference\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003cp\u003e\u003cstrong\u003eNeed a different belt?\u003c\/strong\u003e Browse the full \u003ca href=\"\/collections\/belts\"\u003emower deck belts collection\u003c\/a\u003e.\u003c\/p\u003e","brand":"PTO Direct USA","offers":[{"title":"Default Title","offer_id":53199768093039,"sku":"CAL-285651895023","price":28.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0957\/5058\/6735\/files\/M154621-belt.jpg?v=1783908290","url":"https:\/\/ptodirectusa.com\/products\/deck-belt-m154621","provider":"PTO Direct USA","version":"1.0","type":"link"}