{"product_id":"mercury-quicksilver-gearcase-drain-screw-3-8-16-in-fits-mercruiser-i-r-mr-alpha-one-tr-trs-10-79953q04","title":"Mercury – Quicksilver Gear Lube Drain \u0026 Fill Screw with Seal | Lower Unit Component | 79953Q04","description":"\u003cp data-start=\"0\" data-end=\"100\"\u003e\u003cstrong data-start=\"0\" data-end=\"98\"\u003eMercury – Quicksilver Gear Lube Drain \u0026amp; Fill Screw with Seal | Lower Unit Component | 79953Q04\u003c\/strong\u003e\u003c\/p\u003e\n\u003chr data-start=\"102\" data-end=\"105\"\u003e\n\u003ch3 data-start=\"107\" data-end=\"125\"\u003e\u003cstrong data-start=\"111\" data-end=\"123\"\u003eOverview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"126\" data-end=\"627\"\u003eKeeping your lower unit sealed tight is one of the easiest — and most important — ways to protect your engine’s gears. The \u003cstrong data-start=\"249\" data-end=\"319\"\u003eMercury Marine 79953Q04 Quicksilver Drain and Fill Screw with Seal\u003c\/strong\u003e is designed for \u003cstrong data-start=\"336\" data-end=\"396\"\u003eall MerCruiser sterndrives and Mercury\/Mariner outboards\u003c\/strong\u003e (except Verado models). This non-magnetic plug and seal combination ensures your gear lube stays in and water stays out. It’s a simple part that prevents major damage by keeping your gearcase clean, dry, and properly lubricated.\u003c\/p\u003e\n\u003chr data-start=\"629\" data-end=\"632\"\u003e\n\u003ch3 data-start=\"634\" data-end=\"656\"\u003e\u003cstrong data-start=\"638\" data-end=\"654\"\u003eKey Features\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli data-start=\"659\" data-end=\"747\"\u003e\n\u003cstrong data-start=\"659\" data-end=\"671\"\u003ePurpose:\u003c\/strong\u003e Seals the gear lube drain\/fill hole to prevent leaks and water intrusion.\u003c\/li\u003e\n\u003cli data-start=\"750\" data-end=\"891\"\u003e\n\u003cstrong data-start=\"750\" data-end=\"768\"\u003eCompatibility:\u003c\/strong\u003e Works with \u003cstrong data-start=\"780\" data-end=\"813\"\u003e3\/8-16 drain\/fill hole screws\u003c\/strong\u003e on MerCruiser sterndrives and Mercury\/Mariner outboards (excluding Verado).\u003c\/li\u003e\n\u003cli data-start=\"894\" data-end=\"986\"\u003e\n\u003cstrong data-start=\"894\" data-end=\"905\"\u003eDesign:\u003c\/strong\u003e Includes a \u003cstrong data-start=\"917\" data-end=\"938\"\u003enon-magnetic plug\u003c\/strong\u003e and sealing washer for a tight, reliable fit.\u003c\/li\u003e\n\u003cli data-start=\"989\" data-end=\"1081\"\u003e\n\u003cstrong data-start=\"989\" data-end=\"1005\"\u003ePerformance:\u003c\/strong\u003e Helps maintain correct gear lube levels for smooth, quiet gear operation.\u003c\/li\u003e\n\u003cli data-start=\"1084\" data-end=\"1195\"\u003e\n\u003cstrong data-start=\"1084\" data-end=\"1099\"\u003eDurability:\u003c\/strong\u003e Built from \u003cstrong data-start=\"1111\" data-end=\"1144\"\u003ecorrosion-resistant materials\u003c\/strong\u003e that withstand saltwater and long-term exposure.\u003c\/li\u003e\n\u003cli data-start=\"1198\" data-end=\"1299\"\u003e\n\u003cstrong data-start=\"1198\" data-end=\"1214\"\u003eEase of Use:\u003c\/strong\u003e Installs quickly with a standard screwdriver or wrench during routine maintenance.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"1301\" data-end=\"1304\"\u003e\n\u003ch3 data-start=\"1306\" data-end=\"1343\"\u003e\u003cstrong data-start=\"1310\" data-end=\"1341\"\u003eEngine \u0026amp; Boat Compatibility\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli data-start=\"1346\" data-end=\"1383\"\u003eMerCruiser sterndrives (all models)\u003c\/li\u003e\n\u003cli data-start=\"1386\" data-end=\"1424\"\u003eMercury outboards (excluding Verado)\u003c\/li\u003e\n\u003cli data-start=\"1427\" data-end=\"1465\"\u003eMariner outboards (excluding Verado)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"1467\" data-end=\"1470\"\u003e\n\u003ch3 data-start=\"1472\" data-end=\"1515\"\u003e\u003cstrong data-start=\"1476\" data-end=\"1513\"\u003ePerformance \u0026amp; Real-World Benefits\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"1516\" data-end=\"1846\"\u003eThe \u003cstrong data-start=\"1520\" data-end=\"1553\"\u003e79953Q04 drain and fill screw\u003c\/strong\u003e is a small part with a big job. By sealing the lower unit properly, it prevents water from mixing with gear lube — a leading cause of internal corrosion and bearing wear. Using the included washer ensures the screw seats flush, maintaining proper case pressure and keeping contaminants out.\u003c\/p\u003e\n\u003cp data-start=\"1848\" data-end=\"2008\"\u003eThis OEM replacement helps your gearcase last longer and operate more efficiently. It’s an easy maintenance task that pays off every time you shift into gear.\u003c\/p\u003e\n\u003chr data-start=\"2010\" data-end=\"2013\"\u003e\n\u003ch3 data-start=\"2015\" data-end=\"2047\"\u003e\u003cstrong data-start=\"2019\" data-end=\"2045\"\u003eWhy Choose Mercury OEM\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"2048\" data-end=\"2328\"\u003eThe \u003cstrong data-start=\"2052\" data-end=\"2076\"\u003eQuicksilver 79953Q04\u003c\/strong\u003e is a \u003cstrong data-start=\"2082\" data-end=\"2118\"\u003egenuine Mercury Marine component\u003c\/strong\u003e, designed for an exact fit and tested for sealing reliability. Aftermarket plugs or seals may not match Mercury’s tolerances, leading to minor leaks or poor seating that can cause expensive damage over time.\u003c\/p\u003e\n\u003cp data-start=\"2330\" data-end=\"2549\"\u003eMercury OEM hardware is precision-machined, corrosion-tested, and made from the right materials for marine use. With OEM parts, you know your gearcase is sealed the way Mercury intended — tight, clean, and dependable.\u003c\/p\u003e\n\u003chr data-start=\"2551\" data-end=\"2554\"\u003e\n\u003ch3 data-start=\"2556\" data-end=\"2569\"\u003e\u003cstrong data-start=\"2560\" data-end=\"2567\"\u003eFAQ\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"2571\" data-end=\"2702\"\u003e\u003cstrong data-start=\"2571\" data-end=\"2606\"\u003eQ1: What engines does this fit?\u003c\/strong\u003e\u003cbr data-start=\"2606\" data-end=\"2609\"\u003eIt fits \u003cstrong data-start=\"2617\" data-end=\"2677\"\u003eall MerCruiser sterndrives and Mercury\/Mariner outboards\u003c\/strong\u003e, except Verado models.\u003c\/p\u003e\n\u003cp data-start=\"2704\" data-end=\"2833\"\u003e\u003cstrong data-start=\"2704\" data-end=\"2735\"\u003eQ2: What size is the screw?\u003c\/strong\u003e\u003cbr data-start=\"2735\" data-end=\"2738\"\u003eIt’s made for \u003cstrong data-start=\"2752\" data-end=\"2779\"\u003e3\/8-16 drain\/fill holes\u003c\/strong\u003e, standard on most Mercury and MerCruiser gearcases.\u003c\/p\u003e\n\u003cp data-start=\"2835\" data-end=\"2938\"\u003e\u003cstrong data-start=\"2835\" data-end=\"2864\"\u003eQ3: Is the plug magnetic?\u003c\/strong\u003e\u003cbr data-start=\"2864\" data-end=\"2867\"\u003eNo — this is the \u003cstrong data-start=\"2884\" data-end=\"2908\"\u003enon-magnetic version\u003c\/strong\u003e of the drain and fill plug.\u003c\/p\u003e\n\u003cp data-start=\"2940\" data-end=\"3087\"\u003e\u003cstrong data-start=\"2940\" data-end=\"2977\"\u003eQ4: Why is the seal so important?\u003c\/strong\u003e\u003cbr data-start=\"2977\" data-end=\"2980\"\u003eWithout the proper seal, gear lube can leak out or water can seep in, leading to gear and bearing damage.\u003c\/p\u003e\n\u003cp data-start=\"3089\" data-end=\"3256\"\u003e\u003cstrong data-start=\"3089\" data-end=\"3128\"\u003eQ5: Why OEM instead of aftermarket?\u003c\/strong\u003e\u003cbr data-start=\"3128\" data-end=\"3131\"\u003eMercury OEM plugs and seals guarantee perfect fit, strong corrosion resistance, and reliable sealing performance over time.\u003c\/p\u003e","brand":"Mercury","offers":[{"title":"Default Title","offer_id":46941825171747,"sku":"10-79953Q04","price":5.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0783\/7410\/9475\/files\/79953q04_main.jpg?v=1760631191","url":"https:\/\/partsvu.com\/en-mx\/products\/mercury-quicksilver-gearcase-drain-screw-3-8-16-in-fits-mercruiser-i-r-mr-alpha-one-tr-trs-10-79953q04","provider":"PartsVu","version":"1.0","type":"link"}