We run 5 servo presses (200-600T range) and our PM intervals evolved a lot over the past 4 years. Here's what actually matters vs what the manual says:
The manual says check encoder cables every 6 months. We do it monthly now after losing 3 days of production to an intermittent encoder fault that only showed up under thermal expansion. 5 minutes with a wiggle test at operating temperature saves you a world of pain.
Counterbalance pressure — check weekly, not monthly. We log it on a chart and trend it. A slow leak shows up as 2-3 psi/week drift. By the time you notice it monthly, you've been running with unbalanced load for weeks and wondering why your parts are going out of spec on one side.
One thing nobody puts in their PM schedule but should: drive parameter backup. We do it quarterly and after any parameter change. Store it on a USB in the cabinet AND on the network. Had a drive board fail, replacement came with factory defaults, and the previous maintenance guy had never backed up the tuning parameters. Took 2 days of re-tuning to get back to where we were. Never again.
The thermal imaging tip above is spot on. We added it 2 years ago and it's caught 4 issues before they became failures. Cheap insurance.