John Deere 18-Speed PST Repair Technical Manual (CTM168)

When these Deere machines are pulling heavy tillage tools or running loaders all day, the 18-speed PST transmission is doing the hard work in dust, mud, and temperature swings. This manual is what I keep handy when I need to trace a shifting issue, verify transmission pressures, or go deeper than basic checks. For example, if the tractor starts hunting between gears under load or won’t hold in a certain range, this document guides you through isolating whether it’s mechanical, hydraulic, or electrical before you start stripping components.

Applications & Use Cases

• Trace no-shift or harsh-shift complaints and verify what to test before removing the transmission.
• Inspect and align internal components after teardown so gears, clutches, and shafts go back in correctly.
• Route and identify electrical and hydraulic connections to avoid crossed plugs or misrouted lines.
• Verify adjustments after repair so the PST shifts cleanly under load and at working speed.
• Cross-check parts during ordering so seals, bearings, and hardware match the exact 18-speed setup you’re working on.

FAQ

Q: Can I use this manual on a tablet in the field?

A: Yes, it’s practical to keep a digital copy on a tablet or laptop so you can zoom diagrams and search quickly at the machine.

Q: Is it worth printing sections of this manual?

A: Many techs print the pages they need for a job, mark them up with notes, and keep them at the bench to avoid getting devices oily.

Safety Note

Always depressurize hydraulic and transmission systems and secure the machine before opening, loosening, or testing any components.