{"product_id":"atp-parts-co-4-automatic-transmission-oil-pump-seal","title":"ATP Parts CO-4 Automatic Transmission Oil Pump Seal - Front or Outer","description":"\u003ch2\u003eAutomatic Transmission Oil Pump Seal\u003c\/h2\u003e\u003cp\u003eATP Parts CO-4 is an automatic transmission oil pump seal built to match the listed dimensions for a precise replacement. With a 1.8125\" inside diameter, 3.0\" outside diameter, and 0.4375\" thickness, it supports proper sealing at the transmission pump area on a wide range of classic GM, Jaguar, and Rolls-Royce applications.\u003c\/p\u003e\u003cp\u003eThis ATP transmission seal and gasket replacement follows the brand’s exact-fit approach for direct service work. It is a practical choice when you need a transmission oil pump seal for 1983-1990 Cadillac, Chevrolet, GMC, Jaguar, and Rolls-Royce vehicles with the specified transmission applications.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003ePart number: CO-4\u003c\/li\u003e\n\u003cli\u003eAutomatic transmission oil pump seal for transmission sealing service\u003c\/li\u003e\n\u003cli\u003eDimensions: 1.8125\" ID, 3.0\" OD, 0.4375\" thickness\u003c\/li\u003e\n\u003cli\u003eDirect replacement style for listed fitments\u003c\/li\u003e\n\u003cli\u003eCross-reference: National 6712NA\u003c\/li\u003e\n\u003cli\u003eCross-reference: Pioneer Automotive Industries 759021\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eDetailed Description\u003c\/h2\u003e\u003cp\u003eATP Parts CO-4 is engineered around the listed seal dimensions to help restore the pump-to-case sealing surface in automatic transmissions. It is listed for front-position applications across multiple vehicles, including Chevrolet C10 Suburban, GMC R1500 Suburban, Cadillac Brougham, Jaguar XJ12, and Rolls-Royce Silver Spur, along with many other 1983-1990 models. Fitment notes include specific transmission coverage such as 3L80, THM400, THM425, THM475\/M40, THM350C, THM350, and THM250C\/M31 on certain applications.\u003c\/p\u003e\u003cp\u003eUse CO-4 when replacing a worn or leaking automatic transmission oil pump seal and when the existing seal matches the stated dimensions. This part cross-references National 6712NA and Pioneer Automotive Industries 759021 for the same application.\u003c\/p\u003e\u003ch2\u003eWhat It Helps Fix\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eTransmission fluid seepage at the oil pump seal area\u003c\/li\u003e\n\u003cli\u003eLeaks caused by a hardened or worn pump seal\u003c\/li\u003e\n\u003cli\u003eLoss of sealing integrity during transmission service\u003c\/li\u003e\n\u003cli\u003eIncorrect seal sizing when the original part no longer seals properly\u003c\/li\u003e\n\u003cli\u003eService issues on listed front-position automatic transmission applications\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eInstallation Notes and Tips\u003c\/h2\u003e\u003cp\u003eVerify the seal dimensions before installation: 0.4375\" thickness, 3.0\" outside diameter, and 1.8125\" inside diameter. Confirm the transmission type shown in the fitment notes, especially on vehicles with multiple transmission options such as THM400, THM350C, or 3L80. Clean the sealing bore and mating surfaces before installing the new seal, and inspect the pump area for wear or damage that could affect sealing performance.\u003c\/p\u003e\u003ch2\u003eQuality Assurance\u003c\/h2\u003e\u003cp\u003eATP Transmission Seals and Gaskets are positioned as exact-fit replacement parts for transmission sealing service. ATP Parts CO-4 is built to the listed dimensions for the specified applications, supporting a direct replacement approach for routine transmission repair.\u003c\/p\u003e","brand":"ATP Parts","offers":[{"title":"Default Title","offer_id":43385693012149,"sku":"BBFB-CO-4","price":16.35,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0628\/1442\/1173\/files\/AT_CO4_Fro_3f255c53-5bae-4be5-9c37-1c3912deb10e.jpg?v=1774704541","url":"https:\/\/www.partcatalog.com\/products\/atp-parts-co-4-automatic-transmission-oil-pump-seal","provider":"PartCatalog","version":"1.0","type":"link"}