Dorman 579-021 Fuel Tank Sending Unit Lock Ring

Fuel Tank Sending Unit Lock Ring for Corvette

Dorman 579-021 is a fuel tank sending unit lock ring used to secure the fuel pump assembly at the tank opening. It is made from fiber for dependable service and is recommended whenever the sending unit is serviced. This replacement is a direct fit for select Chevrolet Corvette applications, including 1963-1974 Corvette models with a 3.125 in. inside diameter.

Key Features

• Fuel tank sending unit lock ring for securing the fuel pump assembly
• Fiber construction for reliable service in fuel system applications
• Inside diameter: 3.125 in.; outside diameter: 4 in.
• Includes gasket or seal and mounting hardware
• Direct replacement for Dorman 579-021
• Cross-references Spectra Premium LO21 for the same application

Detailed Description

This Dorman fuel tank sending unit lock ring is built for Chevrolet Corvette fuel system service where a secure retaining ring is required at the tank opening. The fiber material supports stable retention of the sending unit and fuel pump assembly, while the included gasket or seal helps complete the service during replacement. Dorman 579-021 is specified for 1963-1974 Chevrolet Corvette models with a 3.125 in. I.D., making it a focused solution for classic Corvette fuel tank maintenance.

Fits 1963-1974 Chevrolet Corvette, N/A, 3.125 In. I.D. Use Dorman 579-021 when servicing the sending unit on these Corvette applications.

Common Repair Uses

• Replacing a worn or damaged fuel tank sending unit lock ring
• Restoring secure retention of the fuel pump assembly at the tank
• Addressing fuel odor caused by an improper seal at the sending unit opening
• Correcting service issues after tank or sending unit removal
• Supporting fuel system reassembly on classic Chevrolet Corvette models

Installation Notes and Tips

Verify the tank opening diameter before installation and confirm the application matches the 3.125 in. inside diameter specification. Clean the sealing surface thoroughly before installing the gasket or seal, then seat the lock ring evenly to ensure proper retention of the sending unit. For best results, inspect the tank flange and surrounding components for wear or distortion during service.

Quality Assurance

Dorman manufactures replacement hardware for automotive repair applications with attention to fit and serviceability. Part number 579-021 is built as a service replacement for the specified Corvette fuel tank application and is supported by Dorman’s replacement-part engineering standards.