NOTE: RP 624C, Lubricant Fundamentals, was updated in 2023 for TMC's 2023 RP Manual Supplement. The previous version, however, still appears presently in the latest 2024-2025 Recommended Practices Manual. To view the latest RP 624C, goto the 2023 RP Supplement posted here at https://tmcconnect.trucking.org/tmclibraries/new-page