Product Description
Toyota OEM External Retaining Ring, part number TO 00591-00578-81, carbon steel construction, designed for use on Toyota electric lift truck series. Snap style for 3/8 inch shaft groove, heat treated for high retention force. Direct OEM replacement. No cross-reference part numbers available.
Specifications
Dimensional
| Thickness | 0.031 inch |
Material & Construction
| Hardness | Rockwell C45 minimum |
| Finish | Phosphate and oil |
Part Numbers
| OEM Part Number | TO 00591-00578-81 |
| Manufacturer Part Number | 00591-00578-81 |
Frequently Asked Questions
Q: What is the TO 00591-00578-81 retaining ring and what does it do?
A: The TO 00591-00578-81 is a Toyota OEM external snap retaining ring made from carbon steel. It is designed to secure components onto a 3/8 inch shaft groove on Toyota electric lift truck assemblies. It provides axial retention and prevents component movement along the shaft.
Q: What are the specifications of this retaining ring?
A: The TO 00591-00578-81 features a snap-style design for a 3/8 inch shaft groove. Material is carbon steel with a phosphate and oil finish. Thickness is 0.031 inch. Hardness is Rockwell C45 minimum. The ring is heat treated for high retention force and is a direct OEM replacement with no available cross-reference parts.
Q: Is the TO 00591-00578-81 a direct replacement for my Toyota lift truck?
A: Yes. The TO 00591-00578-81 is a direct OEM replacement part for Toyota electric lift truck series that use 3/8 inch shaft snap rings. Verify your lift truck model and shaft groove size before ordering to ensure correct fitment.
Q: What does the phosphate and oil finish do for this retaining ring?
A: The phosphate and oil finish provides corrosion resistance and wear protection. This coating prevents rust and oxidation on the carbon steel ring, extending its service life in the damp or dusty environments typical of warehouse and industrial material handling operations.
Q: How do I know if this retaining ring is worn out?
A: Replace the TO 00591-00578-81 if you observe visible rust or corrosion penetrating the phosphate finish, loss of elasticity or permanent deformation of the ring, component movement or axial play along the shaft, or visible cracks or fractures in the ring material. Heat treatment loss or deformation compromises retention force.
Q: What is the Rockwell C45 hardness specification and why does it matter?
A: Rockwell C45 minimum hardness ensures the ring resists deformation under shaft load and snap engagement cycles. This hardness level, combined with heat treatment, provides the retention force necessary to keep components seated on the 3/8 inch shaft groove and prevents separation during lift truck operation.