{"product_id":"water-pocket-cover-assembly-18-3219-for-mercruiser-alpha-one-merc-i-drives-replaces-42724a3","title":"Sierra Water Pocket Cover Assembly 18-3219, Replaces MerCruiser 42724A3, Alpha One\/Gen II","description":"\u003cp\u003eThe Sierra 18-3219 Water Pocket Cover Assembly is a direct-fit replacement for the drive shaft housing water pocket cover on MerCruiser Alpha One\/Gen II sterndrives. This part is sold as a complete assembly rather than a bare cover, so it comes ready to install without hunting down individual hardware. The assembly bundles the water pocket cover itself along with its mounting screw, gasket, water pump housing bushing, and water tube, giving you every wear component in this section of the drive shaft housing in one package.\u003c\/p\u003e\u003cp\u003eThe water pocket cover directs raw water flow through the drive shaft housing on its way to the water pump and engine cooling system, so a cracked, corroded, or leaking cover can lead to cooling flow problems or water pump housing leaks. Because Sierra ships this as a full assembly, you are also replacing the gasket and bushing at the same time, which is the recommended practice whenever this cover is opened up, since these seal points are the most common source of a repeat leak if only the cover is swapped.\u003c\/p\u003e\u003cp\u003eThis part is cataloged under MerCruiser Alpha One\/Gen II drive shaft housing components and cross-references to MerCruiser OEM number 42724A3. It is intended for use on Mercruiser I and Alpha I stern drives.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-3219\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 42724A3\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSold As:\u003c\/strong\u003e Assembly (includes water pocket cover, mounting screw, gasket, water pump housing bushing, and water tube)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Dimensions:\u003c\/strong\u003e 0.39 x 0.39 x 0.39 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.29 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFinish:\u003c\/strong\u003e Machined\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282243852\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApplication:\u003c\/strong\u003e MerCruiser Alpha One\/Gen II drive shaft housing\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eMerCruiser Alpha One\/Gen II drive shaft housing components\u003c\/li\u003e\n\u003cli\u003eMerCruiser I and Alpha I stern drives\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e42724A3\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-3219 water pocket cover assembly include?\u003c\/strong\u003e The 18-3219 assembly includes the water pocket cover, its mounting screw, a gasket, a water pump housing bushing, and a water tube, so every wear component in that section of the drive shaft housing is replaced in one package rather than sold as a bare cover alone.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat MerCruiser OEM number does part 18-3219 replace?\u003c\/strong\u003e Sierra 18-3219 cross-references to MerCruiser OEM number 42724A3.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat stern drives does the 18-3219 water pocket cover fit?\u003c\/strong\u003e This assembly is cataloged for MerCruiser Alpha One\/Gen II drive shaft housings and fits Mercruiser I and Alpha I stern drives.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs 18-3219 the same as buying just a water tube?\u003c\/strong\u003e No, 18-3219 is the water pocket cover assembly for the drive shaft housing; the water tube is one of the components included in this assembly, but the water tube alone is also available as a separate Sierra part number if the cover itself does not need replacing.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDo I need to replace the gasket separately when installing this cover?\u003c\/strong\u003e No, the Sierra 18-3219 assembly already includes the gasket along with the water pocket cover, mounting screw, bushing, and water tube, so no separate gasket purchase is needed for this repair.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the dimensions of the 18-3219 water pocket cover assembly?\u003c\/strong\u003e The assembly measures 0.39 x 0.39 x 0.39 inches.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-3219 water pocket cover assembly weigh?\u003c\/strong\u003e It weighs 0.29 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat finish does the Sierra 18-3219 water pocket cover have?\u003c\/strong\u003e The cover has a machined finish.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-3219 a genuine Sierra part or aftermarket equivalent?\u003c\/strong\u003e The 18-3219 is a Sierra-branded replacement part manufactured to meet or exceed the specifications of the original MerCruiser 42724A3 water pocket cover it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy replace the bushing and screw along with the cover instead of just the cover itself?\u003c\/strong\u003e Sierra sells 18-3219 as a full assembly with the mounting screw, gasket, and water pump housing bushing included because these are the components most likely to need renewal at the same time as the water pocket cover, reducing the chance of a repeat leak at the drive shaft housing.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat system does the water pocket cover on part 18-3219 serve?\u003c\/strong\u003e The water pocket cover on the 18-3219 assembly is part of the raw water flow path through the MerCruiser Alpha One\/Gen II drive shaft housing, directing cooling water toward the water pump.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988142043355,"sku":"SIE-18-3219","price":34.53,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-3219_lg__27811.1558124349.500.750.jpg?v=1785188184","url":"https:\/\/www.goodvibesmarina.com\/products\/water-pocket-cover-assembly-18-3219-for-mercruiser-alpha-one-merc-i-drives-replaces-42724a3","provider":"Good Vibes Marina","version":"1.0","type":"link"}