{"product_id":"sierra-18-2756-u-joint-bellows-for-mercruiser-stern-drives-replaces-oem-86840a3","title":"Sierra 18-2756 U-Joint Bellows for Mercruiser Bravo I\/II\/III and Blackhawk Stern Drives","description":"\u003cp\u003eThe Sierra 18-2756 U-Joint Bellows is a molded replacement boot that seals the U-joint housing on select MerCruiser stern drives, keeping water out of the drive shaft area and gear lubricant in. It is built from a combination of plastic and rubber for flexibility at the joint while withstanding constant exposure to water and marine grease. The bellows is finished in black and ships as a single unit, ready to install as part of routine stern drive maintenance or as a replacement when the original bellows has cracked, hardened, or begun to leak.\u003c\/p\u003e\u003cp\u003eThis bellows is designed for MerCruiser Bravo I, Bravo II, and Bravo III drives built 1988 and newer with serial number 0B664190 and up, and for MerCruiser Blackhawk drives from 1994-1995 with serial number 0F18677 and up. On both drive families it is used together with the corresponding upper drive bellows and the shared middle bellows as part of a full bellows replacement, which is the standard practice anytime one bellows on the drive is replaced. Keeping the U-joint bellows in good condition is important preventive maintenance, since a torn or deteriorated bellows can allow water intrusion that leads to corrosion and premature U-joint or gimbal bearing failure.\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 18-2756\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Plastic, Rubber\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConstruction Type:\u003c\/strong\u003e Molded\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e Black\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.68 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNumber of Items:\u003c\/strong\u003e 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999621542\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eMercruiser Bravo I\/II\/III, 1988 \u0026amp; Newer, S\/N 0B664190 \u0026amp; Up\u003c\/li\u003e\n\u003cli\u003eMercruiser Blackhawk, 1994-1995, S\/N 0F18677 \u0026amp; Up\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-2756 U-Joint Bellows fit?\u003c\/strong\u003e It fits Mercruiser Bravo I\/II\/III stern drives built 1988 and newer with serial number 0B664190 and up, and Mercruiser Blackhawk drives from 1994-1995 with serial number 0F18677 and up.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is a U-joint bellows used for?\u003c\/strong\u003e The U-joint bellows, part number 18-2756, is a molded boot that seals the U-joint housing on the stern drive, keeping water out and lubricant in around the U-joint area.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the 18-2756 bellows made of?\u003c\/strong\u003e It is molded from a combination of plastic and rubber, finished in black, giving it the flexibility needed at the joint while standing up to constant water and grease exposure.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-2756 U-Joint Bellows weigh?\u003c\/strong\u003e The Sierra 18-2756 U-Joint Bellows weighs 0.68 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many bellows come in the package?\u003c\/strong\u003e One U-Joint Bellows, part number 18-2756, ships per package.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDo I need to check my drive's serial number before ordering?\u003c\/strong\u003e Yes. The 18-2756 bellows applies to Bravo I\/II\/III drives from S\/N 0B664190 and up and Blackhawk drives from S\/N 0F18677 and up, so confirming your drive's serial number ensures correct fitment.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eShould the U-joint bellows be replaced with the other drive bellows?\u003c\/strong\u003e It is standard practice to replace all of the stern drive bellows together, since the 18-2756 U-joint bellows works alongside the drive's other bellows and they tend to wear out around the same time.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are signs the U-joint bellows needs to be replaced?\u003c\/strong\u003e Cracking, hardening, or splitting in the bellows material, or visible water intrusion in the drive shaft area, indicate the U-joint bellows should be replaced.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-2756 bellows a Mercruiser Blackhawk part or a Bravo part?\u003c\/strong\u003e It is used on both: Mercruiser Bravo I\/II\/III drives (1988 \u0026amp; Newer, S\/N 0B664190 \u0026amp; Up) and Mercruiser Blackhawk drives (1994-1995, S\/N 0F18677 \u0026amp; Up).\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is the 18-2756 U-Joint Bellows?\u003c\/strong\u003e The bellows is black.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988111765723,"sku":"SIE-18-2756","price":63.25,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/Untitled-1__46831.1753840676.500.750.jpg?v=1785188090","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-2756-u-joint-bellows-for-mercruiser-stern-drives-replaces-oem-86840a3","provider":"Good Vibes Marina","version":"1.0","type":"link"}