{"product_id":"ultra-1plus-sae-75w-90-synthetic-gear-oil-gl-4-durable-protection","title":"ULTRA 1PLUS SAE 75W-90 Synthetic Gear Oil GL-4 - Durable Protection","description":"\u003cp\u003eIn this review of ULTRA 1PLUS SAE 75W-90 Synthetic Gear Oil GL-4, the bottom line is simple: this 5 gallon pail is aimed at professional mechanics, fleet owners, and enthusiasts who need a robust, year-round gear lubricant that reduces wear under heavy loads. The single biggest reason to buy is its advanced synthetic base and anti-scuffing chemistry that form a stable lubrication film, which customers say improves shift quality and quiets noisy gearboxes in transfer cases and transmissions.\u003c\/p\u003e\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAdvanced GL-4 formula:\u003c\/strong\u003e Premium synthetic base oils provide superior thermal stability and cleanliness to help components run cooler and resist breakdown.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAnti-scuffing protection:\u003c\/strong\u003e Special friction modifiers and anti-scuffing agents guard gears under extreme pressure to minimize pitting and surface wear.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eYear-round viscosity:\u003c\/strong\u003e Meets SAE J306 requirements for all-weather performance so it remains stable across a wide temperature range.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExtended component life:\u003c\/strong\u003e Forms a robust lubrication film that reduces wear on gears and bearings, helping to extend service intervals and lower maintenance costs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLeakage resistance and cleanliness:\u003c\/strong\u003e Formulation reduces leaks and contamination risk while minimizing deposits for a cleaner differential or transmission.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLimited slip additive package:\u003c\/strong\u003e Includes limited slip differential additives for consistent performance in limited slip setups.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eWho It's For\u003c\/h2\u003e\n\u003cp\u003eThe ULTRA 1PLUS 75W-90 GL-4 is best suited to technicians, fleet managers, and vehicle owners who work on automotive axle gears, manual transmissions, transfer cases, and limited slip differentials where GL-4 performance and synthetic stability matter. It is especially useful for high-mileage FWD gearboxes and heavy-use applications where quieter shifting and reduced wear are priorities.\u003c\/p\u003e\n\u003cp\u003eDrivers looking for a budget consumer motor oil replacement for engine use should look elsewhere, and those requiring GL-5 specifications or specific OEM-branded fluids must verify compatibility before switching. This product is primarily formulated for GL-4 applications rather than extreme-pressure GL-5 use.\u003c\/p\u003e\n\u003ch2\u003ePros \u0026amp; Cons\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003ePros\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eDelivers smoother, quieter shifts in transmissions and transfer cases according to customers.\u003c\/li\u003e\n\u003cli\u003ePremium synthetic base oils improve thermal stability and reduce deposit formation for longer component life.\u003c\/li\u003e\n\u003cli\u003eFormulated to meet SAE J306 and exceed API GL-4 standards for dependable year-round viscosity.\u003c\/li\u003e\n\u003cli\u003eIncludes limited slip additives for improved differential performance where required.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eCons\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eSome customers noted mixed opinions on slipperiness and color, indicating subjective differences in feel and appearance.\u003c\/li\u003e\n\u003cli\u003eNot intended for applications that require API GL-5 chemistry without verifying compatibility.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct name\u003c\/td\u003e\n\u003ctd\u003eULTRA 1PLUS SAE 75W-90 Synthetic Gear Oil, API GL-4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eContainer size\u003c\/td\u003e\n\u003ctd\u003e5 Gallon Pail\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eViscosity grade\u003c\/td\u003e\n\u003ctd\u003eSAE 75W-90\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAPI rating\u003c\/td\u003e\n\u003ctd\u003eExceeds API GL-4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMeets\u003c\/td\u003e\n\u003ctd\u003eSAE J306 viscosity requirements\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eKey additives\u003c\/td\u003e\n\u003ctd\u003eAnti-scuffing, friction modifiers, limited slip package\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary benefits\u003c\/td\u003e\n\u003ctd\u003eThermal stability, reduced wear, leakage prevention\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003ch2\u003eOur Verdict\u003c\/h2\u003e\n\u003cp\u003eULTRA 1PLUS 75W-90 GL-4 in a 5 gallon pail is a practical choice for professionals and serious DIYers who need reliable, year-round gear protection and quieter shifting. Its synthetic base and anti-scuffing additives deliver long-term value by extending gear and bearing life, though users must confirm GL-4 compatibility for their specific application.\u003c\/p\u003e\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eCan this be used in limited slip differentials?\u003c\/strong\u003e\u003cbr\u003eYes. The product includes a limited slip differential additive package intended to support limited slip performance.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs this suitable for cold-weather startup?\u003c\/strong\u003e\u003cbr\u003eYes. It meets SAE J306 viscosity requirements for year-round use and maintains adequate lubrication in low temperatures.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill it work in transmissions that previously used GL-5?\u003c\/strong\u003e\u003cbr\u003eNot necessarily; users should verify OEM recommendations and compatibility since this formulation is targeted to API GL-4 applications.\u003c\/p\u003e","brand":"ULTRA 1PLUS","offers":[{"title":"Default Title","offer_id":48637942268123,"sku":"B08HQX1VZ4","price":140.15,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0724\/1043\/1707\/files\/71itbFrQTbL._AC_SL1500.jpg?v=1778614554","url":"https:\/\/gearmusthave.com\/products\/ultra-1plus-sae-75w-90-synthetic-gear-oil-gl-4-durable-protection","provider":"GearMustHave","version":"1.0","type":"link"}