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GM 12587621
Rear Main Seal

2001-2007 GM

Customer Questions & Expert Answers (17)
GM 12587621 Rear Main Seal
  • Part Description
    Seal, Engine Rear Main Bearing; Crankshaft Seal
  • Position
    Rear
  • Replaces
    12559277
  • Manufacturer
    General Motors
Make sure this part fits
$37.56 MSRP: $63.95
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  • Vehicle Fitment

    Year Make Model Trim Engine
    2002-2006 Chevrolet Avalanche 2500Base, LS, LT8 Cyl 8.1 L GAS
    2001-2002 Chevrolet Express 3500Base, LS8 Cyl 8.1 L GAS
    2001-2006 Chevrolet Silverado 2500 HDBase, LS, LT, WT8 Cyl 8.1 L GAS
    2007 Chevrolet Silverado 2500 HD ClassicLS, LT, WT8 Cyl 8.1 L GAS
    2001-2006 Chevrolet Silverado 3500Base, LS, LT, WT8 Cyl 8.1 L GAS
    2007 Chevrolet Silverado 3500 ClassicLS, LT, WT8 Cyl 8.1 L GAS
    2001-2006 Chevrolet Suburban 2500Base, LS, LT8 Cyl 8.1 L GAS
    2001-2002 GMC Savana 3500Base, SLT8 Cyl 8.1 L GAS
    2001-2006 GMC Sierra 2500 HDBase, SL, SLE, SLT, WT8 Cyl 8.1 L GAS
    2007 GMC Sierra 2500 HD ClassicSL, SLE, SLT, WT8 Cyl 8.1 L GAS
    View More
    Warning: California's Proposition 65
  • Customer Questions & Expert Answers

    Q:
    Is this 12587621 designed for my car? Posted by ChevyPartsGiant Specialist
    A:
    Please Select Your Vehicle model to see if part number 12587621 is suitable before ordering.
    Posted by ChevyPartsGiant Specialist
    Q:
    How to replace the rear crankshaft seal on Chevrolet Suburban 2500? Posted by Customer
    A:
    Mount replacement of the Crankshaft rear oil seal requires the disassembly of the Flywheel. The installer positions Crankshaft rear seal puller (J 43320) over guide pins from Crankshaft rear seal puller (J 43320) which have been inserted into the Crankshaft. Using a proper drill install eight self-drilling sheet metal screws across the rear Crankshaft Seal in a cross-pattern. The Crankshaft rear seal puller (J 43320) includes eight self-tapping screws for its installation. The Crankshaft puller assembly requires threads through its central bolt that slips into the Crankshaft to extract the seal. The guide pins should be extracted from the Crankshaft once the seal is removed. Confirm the Crankshaft has no surface abrasions or loose rust or burrs before moving ahead with assembly. Make all necessary corrections beforehand. Dampen the Crankshaft sealing surface with a slender drop of oil while excluding oil from the engine block's sealing surface. Place the Crankshaft rear seal installer (J 42849) on its seal before setting it against the Crankshaft and tightening screws into the facing tapped holes. Using a screwdriver, clamp down the screws on the Crankshaft rear seal installer (J 42849) firmly to achieve square alignment over the Crankshaft before rotating the center nut until complete bottoming occurs. Remove the Crankshaft rear seal installer (J 42849) then reinstall the Flywheel.
    Posted by ChevyPartsGiant Specialist
    Q:
    What is the final step after installing the oil seal for the 2002 Chevrolet Avalanche 2500? Posted by Customer
    A:
    Remove the Front Cover Oil Seal Installer (J 42851) and reinstall the crankshaft balancer.
    Posted by ChevyPartsGiant Specialist
    See expert answers on similar Crankshaft Seal
    Q:
    What is the next step after removing the flywheel for the 2001 Chevrolet Express 3500? Posted by Customer
    A:
    Loosen the oil pan.
    Posted by ChevyPartsGiant Specialist
    See expert answers on similar Crankshaft Seal
    Q:
    How should the outside diameter (OD) of the oil seal and the rear housing oil seal bore be prepared for the 2007 Chevrolet Silverado 3500 Classic? Posted by Customer
    A:
    Lubricate the outside diameter (OD) of the oil seal and the rear housing oil seal bore with clean engine oil.
    Posted by ChevyPartsGiant Specialist
    See expert answers on similar Crankshaft Seal
    Q:
    What is the final step after the oil seal is installed for the 2004 Chevrolet Silverado 3500? Posted by Customer
    A:
    Remove the J 41479 and reinstall the engine flywheel.
    Posted by ChevyPartsGiant Specialist
    See expert answers on similar Crankshaft Seal
    Q:
    What should be avoided when handling the oil seal for the 2007 Chevrolet Silverado 3500 Classic? Posted by Customer
    A:
    Do not lubricate the oil seal sealing surface and avoid reusing the crankshaft oil seal.
    Posted by ChevyPartsGiant Specialist
    See expert answers on similar Crankshaft Seal
    Q:
    How should oil be applied to the crankshaft for the 2006 Chevrolet Avalanche 2500? Posted by Customer
    A:
    Apply a very light film of oil onto the crankshaft sealing surface, avoiding oil on the engine block's sealing surface.
    Posted by ChevyPartsGiant Specialist
    See expert answers on similar Crankshaft Seal
    Q:
    What is the final step after replacing the oil seal for the 2006 Chevrolet Silverado 3500? Posted by Customer
    A:
    Reinstall the crankshaft balancer.
    Posted by ChevyPartsGiant Specialist
    See expert answers on similar Crankshaft Seal
    Q:
    What should be done with the J 41479 threaded rod for the 2006 Chevrolet Silverado 3500? Posted by Customer
    A:
    Thread the J 41479 threaded rod into the tapered cone until it contacts the oil seal, align the oil seal into the tool, and rotate the handle of the tool clockwise until the seal is fully seated in the rear cover bore.
    Posted by ChevyPartsGiant Specialist
    See expert answers on similar Crankshaft Seal
    Q:
    What tool is used to install the new crankshaft front oil seal for the 2001 GMC Savana 3500? Posted by Customer
    A:
    Use the Cover Aligner Seal Installer (J 35468) to install the new seal.
    Posted by ChevyPartsGiant Specialist
    See expert answers on similar Crankshaft Seal
    Q:
    What should be done after positioning the seal for the 2006 GMC Sierra 3500? Posted by Customer
    A:
    Securely tighten the screws with a screwdriver to ensure the seal is installed squarely over the crankshaft.
    Posted by ChevyPartsGiant Specialist
    See expert answers on similar Crankshaft Seal
    Q:
    What is the first step to replace the crankshaft front oil seal for the 2006 GMC Sierra 3500? Posted by Customer
    A:
    Remove the crankshaft balancer, taking care not to damage the engine front cover or the crankshaft sealing area.
    Posted by ChevyPartsGiant Specialist
    See expert answers on similar Crankshaft Seal
    Q:
    What is the process for installing the oil seal for the 2007 GMC Sierra 3500 Classic? Posted by Customer
    A:
    Install the crankshaft front oil seal onto the J 41478 guide, insert the threaded rod into the end of the crankshaft, and use the J 41478 to install the oil seal into the cover bore.
    Posted by ChevyPartsGiant Specialist
    See expert answers on similar Crankshaft Seal
    Q:
    What should be verified after installing the crankshaft front seal for the 2002 GMC Savana 3500? Posted by Customer
    A:
    That the crankshaft front seal is flush and square to the engine front cover.
    Posted by ChevyPartsGiant Specialist
    See expert answers on similar Crankshaft Seal
    Q:
    What should be done after tightening the oil pan for the 2002 GMC Savana 3500? Posted by Customer
    A:
    Reinstall the flywheel.
    Posted by ChevyPartsGiant Specialist
    See expert answers on similar Crankshaft Seal
    Q:
    What should be done before installing the new oil seal for the 2007 GMC Sierra 3500 Classic? Posted by Customer
    A:
    Inspect the seal for proper orientation.
    Posted by ChevyPartsGiant Specialist
    See expert answers on similar Crankshaft Seal
    If you have any questions about this product, please don't hesitate to ask us. We will be happy to help you!

OEM GM Rear Main Seal 12587621 Designed for Proper Fit and Performance

Original OEM GM parts deliver superior quality and meet all performance standards needed for optimal automotive operation. The authentic part identified by 12587621 Rear Main Seal is available in the market under the name GM Crankshaft Seal. This genuine product has a full warranty coverage from the manufacturer available at all authorized GM dealers throughout the United States. This part 12587621 Rear Main Seal fits certain Chevrolet Silverado 2500 HD, Express 3500, Silverado 3500 models, as well as GMC Sierra 2500 HD, Savana 3500, Sierra 3500 models.
The original GM component designated by manufacturer part number 12587621 maintains top performance when functioning as the Seal, Engine Rear Main Bearing; Crankshaft Seal unit at its Rear. The component 12587621 is constructed from durable material and its dimensions span 5.3 x 5.5 x 0.6 inches while weighing 0.50 Pounds. The Direct Replacement component is ready in New condition to ensure full compatibility with your vehicle system. The part 12587621 has available replacement options 12559277. GM manufacturer provides a warranty that ensures reliable operation of this product. The Shipping Policy and Return Policy pages outline complete details regarding shipping procedures and return processes.
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