{"product_id":"sierra-18-99164-upper-unit-casing-gasket-for-yamaha-outboard-gearcase-drive-applications","title":"Sierra Upper Unit Casing Gasket 18-99164 for Yamaha Outboard Gearcase","description":"\u003cp\u003eThe Sierra Upper Unit Casing Gasket, part number 18-99164, is a replacement gasket designed for use in the upper unit casing of Yamaha outboard gearcase and drive systems. This gasket seals the mating surfaces of the upper casing to help maintain proper lubrication levels and prevent water intrusion into the gearcase, both of which are essential to protecting internal gears and bearings from corrosion and premature wear. Installing a fresh gasket whenever the upper casing is opened for service, such as during a gear lube change, seal replacement, or gearcase inspection, helps ensure a reliable seal is restored rather than reusing a compressed or damaged original gasket. Sierra manufactures this gasket for the marine aftermarket as a direct fit for the Yamaha outboard gearcase and drive parts application it is designated for. Keeping a gasket like this on hand is useful for routine maintenance and repair work on outboard lower units, since a compromised gasket can lead to lubricant loss or water contamination that damages gearcase components.\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 18-99164\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Name:\u003c\/strong\u003e Upper Unit Casing Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApplication:\u003c\/strong\u003e Yamaha Outboard Gearcase \u0026amp; Drive Parts\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.05 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Dimensions:\u003c\/strong\u003e 4 x 4 x 0.5 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282385781\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eYamaha outboard gearcase and drive systems (upper unit casing)\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat is the Sierra 18-99164 gasket used for?\u003c\/strong\u003e Sierra part number 18-99164 is an upper unit casing gasket used to seal the upper casing of a Yamaha outboard gearcase and drive system, helping keep gear lubricant in and water out.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-99164 gasket fit Yamaha outboards?\u003c\/strong\u003e Yes, the 18-99164 upper unit casing gasket is designated for Yamaha outboard gearcase and drive parts applications.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-99164 gasket weigh?\u003c\/strong\u003e The Sierra Upper Unit Casing Gasket, part number 18-99164, weighs 0.05 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the package dimensions of this gasket?\u003c\/strong\u003e The 18-99164 gasket ships in packaging measuring 4 x 4 x 0.5 inches.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs 18-99164 a genuine Sierra part number?\u003c\/strong\u003e Yes, 18-99164 is the Sierra manufacturer part number for this Upper Unit Casing Gasket, not a supplier or retailer code.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen should the upper unit casing gasket be replaced?\u003c\/strong\u003e This gasket should be replaced any time the upper casing on the Yamaha outboard gearcase is opened for service, such as during a gear lube change or gearcase inspection, since a reused gasket may not seal properly.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat happens if the upper casing gasket fails or is not replaced?\u003c\/strong\u003e A worn or damaged upper unit casing gasket like 18-99164 can allow gear lubricant to leak out or water to enter the gearcase, both of which can lead to corrosion and damage to internal gears and bearings.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when ordering part 18-99164?\u003c\/strong\u003e Ordering Sierra 18-99164 includes one Upper Unit Casing Gasket sized for the Yamaha outboard gearcase upper casing application.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-99164 gasket an OEM or aftermarket part?\u003c\/strong\u003e The 18-99164 Upper Unit Casing Gasket is manufactured by Sierra for the marine aftermarket as a replacement part for Yamaha outboard gearcase applications.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan this gasket be reused after removal?\u003c\/strong\u003e No, gaskets such as the Sierra 18-99164 are designed for one-time use; once the upper casing is disassembled, a new gasket should be installed to ensure a proper seal.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988437676251,"sku":"SIE-18-99164","price":39.7,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/18-99164__35951.1739477163.500.750.jpg?v=1785188329","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-99164-upper-unit-casing-gasket-for-yamaha-outboard-gearcase-drive-applications","provider":"Good Vibes Marina","version":"1.0","type":"link"}