National 4583 Manual Transmission Output Shaft Seal

Manual Transmission Output Shaft Seal for GM Applications

National 4583 is a manual transmission output shaft seal built for leak control at the transmission tailshaft area. It uses a polyacrylate sealing material, a counter-clockwise spiral lip design, and Redicoat surface treatment to support a consistent seal on the shaft and housing bore.

With fitment across a wide range of Chevrolet, GMC, Cadillac, Buick, Hummer, Isuzu, Pontiac, Saab, and Oldsmobile vehicles, this seal is a direct replacement choice for many GM 4L60-E and 4L65-E transmission applications. National 4583 is also cross-referenced to 24204540 and 24232324 for the same application.

Key Features

• Part number: 4583
• Manual transmission output shaft seal / oil seal
• Polyacrylate sealing material for transmission fluid sealing
• Counter-clockwise spiral lip design
• Redicoat treated sealing surface
• Inside diameter: 1.502 in. / 38.150 mm
• Outside diameter: 2.381 in. / 60.480 mm
• Width: 0.374 in. / 9.500 mm
• Housing bore: 2.377 in. / 60.380 mm
• Flanged outside diameter: 2.717 in. / 69.000 mm

Detailed Description

National 4583 is part of the 4000 series and is engineered as a transmission sealing component for output shaft service. The polyacrylate material is selected for sealing performance in transmission environments, while the spiral lip geometry helps maintain contact at the shaft interface. Its dimensions are specified in both inch and metric units for accurate service matching.

This seal is used in many GM rear-wheel-drive and truck/SUV platforms, including Chevrolet Silverado 1500, Tahoe, Trailblazer, Express, GMC Sierra 1500, Yukon, Envoy, and related models. If you are servicing a Chevrolet Silverado 1500 or GMC Sierra 1500 with a 4L60-E or 4L65-E transmission, National 4583 is a direct-fit output shaft seal reference to verify against your original part.

What It Helps Fix

• Transmission fluid leaking from the output shaft area
• Wet or contaminated tailshaft housing surfaces
• Seal wear from age, heat, or fluid exposure
• Service issues during manual transmission output shaft seal replacement
• Fitment concerns when replacing an OE-style GM transmission seal

Installation Notes and Tips

Confirm the shaft diameter, housing bore, and seal width before installation. This part is listed for applications without a boot in many vehicle notes, so verify the original configuration on the transmission before ordering. Clean the bore and shaft surface thoroughly, and inspect for grooves, scoring, or housing damage that could affect sealing performance.

For fitment research, this seal is listed across 1984-2014 model years and includes applications such as Chevrolet Express 1500, GMC Savana 1500, Chevrolet Silverado 1500, GMC Sierra 1500, and Chevrolet Tahoe. Always match the transmission type and original seal style to the vehicle application.

Quality Assurance

National has supplied sealing solutions for more than 75 years and focuses on advanced sealing designs for modern vehicles. Part number 4583 reflects that experience with a transmission seal built to meet the dimensional and material requirements of the listed applications.