{"product_id":"yukon-gear-dura-grip-positraction-for-gm-12-bolt-car-w-30-spline-axles-3-73","title":"Yukon Gear Dura Grip Positraction For GM 12 Bolt Car w\/ 30 Spline Axles \/ 3.73+","description":"\u003ch4\u003eYukon Gear DuraGrip Positraction for GM 12 Bolt Car with 30 Spline Axles and 3.73 and Up Ratios\u003c\/h4\u003e\n\u003cp\u003eClassic GM muscle car and truck owners running 3.73 and numerically higher gear ratios will find the \u003cstrong\u003eYDGGM12T-4-30-1\u003c\/strong\u003e Yukon Gear DuraGrip to be the definitive upgrade for the GM 12-bolt rear axle. Part number \u003cstrong\u003eYDGGM12T-4-30-1\u003c\/strong\u003e is engineered specifically for 12-bolt housings equipped with 30-spline axle shafts and higher gear ratios, which require the wider carrier spread found in this unit. The \u003cstrong\u003eYDGGM12T-4-30-1\u003c\/strong\u003e uses a forged 4320 chromoly spider gear set inside a high-strength nodular iron case to deliver smooth, progressive torque transfer to both rear wheels without requiring the wheel speed difference needed to activate a locker. Whether you are building a street cruiser, a weekend drag car, or a vintage off-road truck, this \u003cstrong\u003eYDGGM12T-4-30-1\u003c\/strong\u003e DuraGrip keeps both tires working together.\u003c\/p\u003e\n\n\u003ch4\u003eFeatures and Benefits\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eFits GM 12-bolt truck (12T) rear differential housing with 30-spline axle shafts\u003c\/li\u003e\n  \u003cli\u003eDesigned for 3.73 and numerically higher gear ratios only (requires the wide-spread carrier)\u003c\/li\u003e\n  \u003cli\u003e4-spring, clutch-style positraction for smooth torque transfer under acceleration\u003c\/li\u003e\n  \u003cli\u003eForged 4320 chromoly steel spider gears cut to provide maximum tooth strength\u003c\/li\u003e\n  \u003cli\u003eHigh-strength nodular iron case for crack resistance under extreme loads\u003c\/li\u003e\n  \u003cli\u003eComposite clutch packs for reduced chatter and extended life\u003c\/li\u003e\n  \u003cli\u003eFully rebuildable with available replacement clutch packs\u003c\/li\u003e\n  \u003cli\u003eAssembled in the United States\u003c\/li\u003e\n  \u003cli\u003eCompatible with carrier bearing part numbers included in tech notes\u003c\/li\u003e\n  \u003cli\u003eOne-year warranty against manufacturer defects\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch4\u003eVehicle Fitment\u003c\/h4\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eYear\u003c\/th\u003e\n\u003cth\u003eMake\u003c\/th\u003e\n\u003cth\u003eModel\u003c\/th\u003e\n\u003cth\u003eTrim\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1963\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1964\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1965\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1966\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1967\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1968\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1969\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1970\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1971\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1972\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1973\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10\u003c\/td\u003e\n\u003ctd\u003eCheyenne\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1974\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10\u003c\/td\u003e\n\u003ctd\u003eCheyenne\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1975\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10\u003c\/td\u003e\n\u003ctd\u003eCheyenne\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1976\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10\u003c\/td\u003e\n\u003ctd\u003eCheyenne\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1977\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10\u003c\/td\u003e\n\u003ctd\u003eCheyenne\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1978\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10\u003c\/td\u003e\n\u003ctd\u003eCheyenne\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1979\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10\u003c\/td\u003e\n\u003ctd\u003eCheyenne\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1980\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10\u003c\/td\u003e\n\u003ctd\u003eCheyenne\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1981\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1982\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1983\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1984\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1985\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1986\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1987\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eC10\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1963\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eK10 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1964\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eK10 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1965\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eK10 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1966\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eK10 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1967\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eK10 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1968\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eK10 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1969\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eK10 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1970\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eK10 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1971\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eK10 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1972\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eK10 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1969\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eBlazer\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1970\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eBlazer\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1971\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eBlazer\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1972\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eBlazer\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1973\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eBlazer\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1974\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eBlazer\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1987\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eBlazer\u003c\/td\u003e\n\u003ctd\u003eCustom Deluxe\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1963\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eSuburban\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1964\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eSuburban\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1965\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eSuburban\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1966\u003c\/td\u003e\n\u003ctd\u003eChevrolet\u003c\/td\u003e\n\u003ctd\u003eSuburban\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1967\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eC15\/C1500 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1968\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eC15\/C1500 Pickup\u003c\/td\u003e\n\u003ctd\u003eCustom\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1979\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eC1500\u003c\/td\u003e\n\u003ctd\u003eHigh Sierra\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1980\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eC1500\u003c\/td\u003e\n\u003ctd\u003eHigh Sierra\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1981\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eC1500\u003c\/td\u003e\n\u003ctd\u003eHigh Sierra\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1982\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eC1500\u003c\/td\u003e\n\u003ctd\u003eHigh Sierra\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1983\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eC1500\u003c\/td\u003e\n\u003ctd\u003eHigh Sierra\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1984\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eC1500\u003c\/td\u003e\n\u003ctd\u003eHigh Sierra\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1985\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eC1500\u003c\/td\u003e\n\u003ctd\u003eHigh Sierra\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1986\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eC1500\u003c\/td\u003e\n\u003ctd\u003eHigh Sierra\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1987\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eR1500\u003c\/td\u003e\n\u003ctd\u003eHigh Sierra\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch4\u003eSpecifications\u003c\/h4\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003ePart Number\u003c\/td\u003e\n\u003ctd\u003eYDGGM12T-4-30-1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eUPC\u003c\/td\u003e\n\u003ctd\u003e883584260356\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eDifferential\u003c\/td\u003e\n\u003ctd\u003eGM 8.875 inch 12-Bolt Truck (12T) Rear\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eRing Gear Diameter\u003c\/td\u003e\n\u003ctd\u003e8.875 inches (12-bolt truck)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eRing Gear Bolts\u003c\/td\u003e\n\u003ctd\u003e12\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eAxle Spline Count\u003c\/td\u003e\n\u003ctd\u003e30\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eGear Ratio Compatibility\u003c\/td\u003e\n\u003ctd\u003e3.73 and numerically higher only\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eClutch-Style Limited Slip Differential (DuraGrip)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e1 Year Manufacturer Warranty\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch4\u003eWhat Is Included\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eOne fully assembled DuraGrip positraction carrier\u003c\/li\u003e\n  \u003cli\u003eComposite clutch packs and 4-spring preload assembly pre-installed\u003c\/li\u003e\n  \u003cli\u003eForged 4320 chromoly spider gears installed\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch4\u003eFrequently Asked Questions\u003c\/h4\u003e\n\u003cp\u003e\u003cstrong\u003eWhy does YDGGM12T-4-30-1 only fit 3.73 and higher ratios?\u003c\/strong\u003e\u003cbr\u003eThe GM 12-bolt uses two different carrier spreads. Lower ratios (2.76 through 3.42) require the narrow-spread carrier, while 3.73 and higher require the wide-spread carrier. The \u003cstrong\u003eYDGGM12T-4-30-1\u003c\/strong\u003e is the wide-spread version for 3.73 and up.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes YDGGM12T-4-30-1 fit the 12-bolt passenger car axle?\u003c\/strong\u003e\u003cbr\u003eNo. The \u003cstrong\u003eYDGGM12T-4-30-1\u003c\/strong\u003e is designed for the 12-bolt truck (8.875 inch ring gear). The 12-bolt passenger car uses a smaller 8.2 inch ring gear with a different carrier. See YDGGM8.2-3-28-1 for the car application.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat spline count does this unit require?\u003c\/strong\u003e\u003cbr\u003eThe \u003cstrong\u003eYDGGM12T-4-30-1\u003c\/strong\u003e is designed for 30-spline axle shafts. If your 12-bolt axle has 28-spline shafts, this unit will not fit.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs this unit compatible with factory 12-bolt ring gear bolts?\u003c\/strong\u003e\u003cbr\u003eYes, the unit accepts standard 12-bolt truck ring gear hardware. Ensure bolts are torqued to the correct specification during installation.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes the Magnuson-Moss Warranty Act protect my classic truck after this installation?\u003c\/strong\u003e\u003cbr\u003eUnder the Magnuson-Moss Warranty Act, installing an aftermarket differential such as the \u003cstrong\u003eYDGGM12T-4-30-1\u003c\/strong\u003e does not void an existing warranty unless the manufacturer proves the part caused the failure in question.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat gear oil should I use with YDGGM12T-4-30-1?\u003c\/strong\u003e\u003cbr\u003eYukon Gear recommends high-grade non-synthetic GL-5 gear oil combined with Yukon LSD additive (part number OILADD). Synthetic oil is not recommended and may cause chatter or aggressive engagement.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I use this with factory 12-bolt spider gears?\u003c\/strong\u003e\u003cbr\u003eNo. The \u003cstrong\u003eYDGGM12T-4-30-1\u003c\/strong\u003e is a complete carrier assembly with its own internal spider gears and clutch packs. It replaces the entire open differential carrier.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow do I know which carrier spread my 12-bolt has?\u003c\/strong\u003e\u003cbr\u003eIdentify your gear ratio via axle tag or VIN decode. Ratios of 2.76, 3.08, 3.31, and 3.42 use the narrow spread. Ratios of 3.73, 4.10, 4.56, and 4.88 use the wide spread. The YDGGM12T-4-30-1 fits the wide-spread (3.73 and up) application.\u003c\/p\u003e\n\n\u003ch4\u003eInstallation Instructions\u003c\/h4\u003e\n\u003col\u003e\n  \u003cli\u003eDrain differential fluid and remove the cover, driveshaft, and axle shafts.\u003c\/li\u003e\n  \u003cli\u003eMark bearing caps for position, then remove them and extract the original carrier with side bearing shims.\u003c\/li\u003e\n  \u003cli\u003eRemove the ring gear from the original carrier and transfer it to the new YDGGM12T-4-30-1 unit using correct torque on ring gear bolts.\u003c\/li\u003e\n  \u003cli\u003eInstall side bearings on the new carrier if not already pressed on. Reinstall with the original shims as a starting point.\u003c\/li\u003e\n  \u003cli\u003eSet backlash to 0.006 to 0.010 inch using a dial indicator. Adjust side shims as needed.\u003c\/li\u003e\n  \u003cli\u003eConfirm carrier bearing preload and gear contact pattern with marking compound.\u003c\/li\u003e\n  \u003cli\u003eReinstall bearing caps to their original side and torque to specification.\u003c\/li\u003e\n  \u003cli\u003eClean the cover sealing surface and reinstall the cover. Fill with GL-5 oil and LSD additive.\u003c\/li\u003e\n  \u003cli\u003eReinstall axle shafts and driveshaft. Verify all fastener torques.\u003c\/li\u003e\n  \u003cli\u003eBreak in the new unit with 500 miles of normal driving before towing or performance use.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003e\u003cstrong\u003eProposition 65 Warning:\u003c\/strong\u003e This product can expose you to chemicals including arsenic, which is known to the State of California to cause cancer. For more information, go to \u003ca href=\"https:\/\/www.P65Warnings.ca.gov\"\u003ewww.P65Warnings.ca.gov\u003c\/a\u003e.\u003c\/p\u003e","brand":"Yukon Gear \u0026 Axle","offers":[{"title":"Default Title","offer_id":40481862647887,"sku":"YUKYDGGM12T-4-30-1","price":919.89,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1062\/7920\/files\/yukon-gear-dura-grip-positraction-for-gm-12-bolt-car-w-30-spline-axles-3_73-differentials-yukon-gear-axle-4.jpg?v=1701888270","url":"https:\/\/www.blackopsautoworks.com\/products\/yukon-gear-dura-grip-positraction-for-gm-12-bolt-car-w-30-spline-axles-3-73","provider":"Black Ops Auto Works","version":"1.0","type":"link"}