{"product_id":"star-brite-synthetic-blend-lower-unit-gear-lube-80w-90-marine-grade-1-qt-api-gl-5-rust-protection","title":"STAR BRITE Synthetic Blend Lower Unit Gear Lube 80W-90 Marine Grade — 1 qt, API GL-5 \u0026 Rust Protection","description":"\u003cp\u003e\u003cstrong\u003eSTAR BRITE Synthetic Blend Lower Unit Gear Lube 80W-90 is a marine-grade gear oil formulated to protect outboard lower units from wear, rust, and thermal breakdown while meeting API GL-5, MT-1, SAE J2360, and Mack GO-J specifications.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eBuilt as a high-viscosity synthetic blend, this 80W-90 gear lube is intended for modern marine lower units—especially higher-horsepower outboards—where long-term corrosion prevention and extreme-pressure protection are required. The formulation combines base oils and targeted additives to stabilize viscosity under load, resist oxidation, and shield gears and bearings from scoring and rust in saltwater and freshwater environments.\u003c\/p\u003e\n\n\u003ch3\u003eHow does this gear lube protect my lower unit during heavy use?\u003c\/h3\u003e\n\u003cp\u003eThe oil includes extreme-pressure and anti-wear additives that form a protective film on gear surfaces, helping the drivetrain resist metal-to-metal contact under high load and elevated temperatures. It also contains rust-inhibiting components to limit corrosion when water contamination or humid storage occurs.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eExtreme-pressure additives reduce gear pitting during torque spikes.\u003c\/li\u003e\n  \u003cli\u003eAnti-wear agents preserve bearings and gear teeth under continuous load.\u003c\/li\u003e\n  \u003cli\u003eRust inhibitors protect exposed internals from corrosion between outings.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWill this 80W-90 meet my engine and spec requirements?\u003c\/h3\u003e\n\u003cp\u003eSTAR BRITE Synthetic Blend 80W-90 is formulated to satisfy common marine and heavy-duty specifications—API GL-5, API MT-1, SAE J2360, and Mack GO-J—so it’s compatible with many lower units that require those approvals. It is recommended for engines over 100 hp but can also be used wherever 80W-90 GL-5 gear oil is specified.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eMeets API GL-5 for hypoid and spiral-bevel gears.\u003c\/li\u003e\n  \u003cli\u003eComplies with MT-1 and SAE J2360 test criteria relevant to marine gear oils.\u003c\/li\u003e\n  \u003cli\u003eSuitable upgrade for applications calling for Mack GO-J performance.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow do I change and install this marine gear lube correctly?\u003c\/h3\u003e\n\u003cp\u003eChanging lower unit oil is straightforward: drain the old lubricant, fit the appropriate fill tube or adapter, refill to the manufacturer-specified volume, and reseal the plugs. STAR BRITE supplies compatible quart pumps, lube tubes, and adaptors to streamline filling and reduce mess.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eDrain old fluid and inspect for metal particles or water.\u003c\/li\u003e\n  \u003cli\u003eUse STAR BRITE fill tools to avoid spills and ensure correct venting.\u003c\/li\u003e\n  \u003cli\u003eRefill to factory level and torque drain\/fill plugs per OEM specs.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat performance benefits can I expect compared to conventional oils?\u003c\/h3\u003e\n\u003cp\u003eThe synthetic blend offers improved thermal stability and shear resistance versus many straight-mineral 80W-90 fluids, helping maintain film strength under sustained heat and load. That translates to reduced wear, longer service intervals when following manufacturer guidance, and better protection in challenging marine conditions.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eGreater viscosity control at high operating temperatures.\u003c\/li\u003e\n  \u003cli\u003eEnhanced protection during repeated load cycles and long runs.\u003c\/li\u003e\n  \u003cli\u003eEffective in both saltwater and freshwater use when properly sealed and maintained.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for? Boaters, pro technicians, and DIY marine owners with outboard engines—especially units above 100 hp—who want a robust, specification-compliant gear oil to protect lower units from wear, corrosion, and heat-related breakdown. If you value easy servicing, proven industry specs, and a product from a long-established marine brand, STAR BRITE Synthetic Blend 80W-90 is engineered to be a dependable choice for routine gear-lube maintenance and upgrades.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Is STAR BRITE 80W-90 suitable for saltwater use?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. Formulated with rust inhibitors and extreme-pressure additives, it protects gears and bearings in saltwater when seals are intact.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can I use this oil in engines under 100 hp?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: You can, if your lower unit calls for 80W-90 GL-5 gear oil, but it’s recommended primarily for engines over 100 hp.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"STAR BRITE","offers":[{"title":"Default Title","offer_id":48086815768734,"sku":"B000RZSJJM","price":34.46,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/star-brite-lower-unit-bottle-front.jpg?v=1785906329","url":"https:\/\/northtrailauto.ca\/products\/star-brite-synthetic-blend-lower-unit-gear-lube-80w-90-marine-grade-1-qt-api-gl-5-rust-protection","provider":"North Trail Auto","version":"1.0","type":"link"}