ATP Parts SO-39 Automatic Transmission Accumulator Cover Gasket

Automatic Transmission Accumulator Cover Gasket

ATP Parts SO-39 is an automatic transmission accumulator cover gasket for select GM rear-wheel-drive applications. It is built as an exact-fit replacement to help restore a proper seal at the intermediate piston cover and aluminum large accumulator cover.

With a 2.625-inch outside diameter and 2.3125-inch inside diameter, this gasket is specified for THM350C applications noted in the fitment data and is used across a wide range of Chevrolet, GMC, Buick, Oldsmobile, Pontiac, and Cadillac vehicles from 1979-1988.

• Part number: SO-39
• 2.625 in. outside diameter
• 2.3125 in. inside diameter
• Exact-fit replacement for select automatic transmission accumulator covers
• Fits intermediate piston cover and aluminum large accumulator cover applications
• Cross-references Remy 14879 for the same application

Detailed Fitment and Application

ATP Parts SO-39 is a transmission sealing component used where the accumulator cover meets the transmission case or related cover surface. In the listed applications, it serves GM vehicles including Chevrolet C10, Chevrolet K5 Blazer, GMC G3500, and Pontiac Grand Prix, along with many other 1979-1988 models. For buyers searching for a Chevrolet C10 transmission accumulator cover gasket, GMC G3500 automatic transmission gasket, or SO-39 replacement seal, this part number matches the specified dimensions and application notes.

This part cross-references Remy 14879 for the same application.

What This Part Helps Address

• Transmission fluid seepage around the accumulator cover
• Loss of sealing at the intermediate piston cover
• Service replacement for worn or flattened gasket material
• Fitment correction during THM350C transmission repair
• Leak repair on select Chevrolet, GMC, Buick, Oldsmobile, Pontiac, and Cadillac vehicles

Installation Notes and Tips

Confirm the cover style and transmission type before installation. The fitment notes specify aluminum large accumulator cover and intermediate piston cover applications, with some listings calling out THM350C only. Clean both sealing surfaces thoroughly, verify the gasket dimensions against the removed part, and inspect the cover for warpage or damage before reassembly.

Quality Assurance

ATP Transmission Seals and Gaskets are exact-fit replacement parts made for direct service use in transmission sealing applications. SO-39 follows the listed OE-style dimensions and application notes for accurate replacement on the specified vehicles.