ATP Parts JO-124 Automatic Transmission Extension Housing Seal

Automatic Transmission Extension Housing Seal

ATP Parts JO-124 is an automatic transmission extension housing seal with boot made for exact-fit replacement service. It is built to match the original dimensions and sealing profile for a direct repair on a wide range of GM trucks, vans, and select luxury applications.

Use this seal when servicing the transmission output area on vehicles such as Chevrolet Silverado, GMC Sierra, Chevrolet Express, and GMC Savana models. The JO-124 helps restore a proper seal at the extension housing where the driveshaft exits the transmission.

Key Features

• Exact-fit replacement from ATP Parts
• Automatic transmission extension housing seal with boot
• Dimensions: 1.625" W x 3.125" OD x 2.0625" ID
• Direct replacement for common GM truck, van, and SUV applications
• Cross-references BBB Industries 16450 and Four Seasons 4333N for the same application
• Part number JO-124 for easy ordering and catalog lookup

Detailed Description

ATP Transmission Seals and Gaskets are positioned as exact-fit replacement parts, and this JO-124 extension housing seal follows that approach with application-specific sizing and a booted design. It is listed across many 1994-2009 vehicles, including Chevrolet Silverado 1500, Silverado 2500 HD, Suburban 2500, GMC Sierra 1500, Sierra 2500 HD, Savana 2500, and Chevrolet Express 2500. It also appears in fitment for Bentley, Rolls-Royce, Aston Martin, Jaguar, Cadillac, and Hummer applications where the same seal dimensions are used.

Fits 1994-2000 Chevrolet C2500, N/A; Fits 1995-2000 GMC K3500, N/A; Fits 2001-2006 Chevrolet Silverado 2500 HD, N/A; Fits 2000-2007 GMC Yukon XL 2500, N/A; Fits 1996-2009 Chevrolet Express 3500, N/A.

Common Repair Uses

• Transmission fluid leakage at the extension housing
• Worn or hardened output seal material
• Boot damage around the driveshaft exit area
• Seal replacement during transmission service or driveline repair
• Restoring a proper seal after driveline removal

Installation Notes and Tips

Verify the seal dimensions and transmission application before installation. Clean the extension housing bore and inspect the output shaft surface for wear, scoring, or contamination before pressing in the new seal. Confirm the boot seats evenly and that the sealing lip is oriented correctly for the transmission design.

Quality Assurance

ATP Parts markets this seal as an exact-fit replacement component for transmission sealing service. The JO-124 is built to match the listed application dimensions and OE-style fitment requirements for dependable repair work.