An ABB IRB 2400 on an S4 cabinet and another IRB 2400 on an S4C do not run the same oil in the wrist. An IRB 6400 with S4 has four axes lubricated with grease, not oil. And an IRB 4400 with S4 has no scheduled oil change in its gearboxes, but it does have other tasks with a due date. On ABB robots from the S4, S4C and S4C+ generations, the maintenance plan depends on the generation as much as on the model. That is why, on a robot from that era, the first thing we look at is not the hour counter but which manual applies to it.
Why the same ABB model changes plan between S4, S4C and S4C+
Several ABB manipulators (IRB 1400, 2400, 4400, 6400) were built for years while the controller moved from S4 to S4C and then to S4C+ (M2000, running BaseWare OS 4.0). The robot's commercial name stayed the same; the Product Manual did not. The IRB 2400/2400L, for example, has worked with S4, S4C and S4C+ M2000 cabinets. ABB still treats S4, S4C and S4C plus as separate generations in its documentation.
The manuals follow the system version, and that version indicates the generation. These are the pairings in our technical database:
- IRB 1400: with S4, manual M94; with S4C, M98.
- IRB 2400: with S4, M96; with S4C, M98A.
- IRB 4400 with S4: M94A.
- IRB 6400 with S4: M96.
- S4C+ cabinet: M2000.
The paint variants (S4P and S4P plus) are a separate controller branch and fall outside what we cover here.
How to tell which manual applies to each robot
Before planning anything, these are the checks we make robot by robot:
- Manipulator rating plate: exact model and variant. A standard IRB 2400 is not a 2400L, and the wrist reflects the difference.
- Cabinet: S4, S4C or S4C+. On an S4C+, the configuration shows BaseWare OS 4.0 or System Pack 4.0.
- The manual version on site (M94, M96, M98, M2000…) and whether it matches the manipulator–cabinet pairing in front of you.
- The robot's history: if it came from another line or from a refurbishment, check the pairing again. The manual that travels with the machine is not always its own.
- The plan in the CMMS: lubricants, tasks and intervals must come from that generation's manual, not from a later model's or from a generic plan.
IRB 2400: same main axes, different wrist
On the IRB 2400, the gearboxes on axes 1 to 3 carry ISO VG 320 oil “for life” with both S4 and S4C. So far, identical. The difference is in the wrist: with S4, 75W-90 gear oil; with S4C, in the standard version, Optigear BM 100. The long-reach version, the 2400L, takes a different oil in the wrist. That makes three robots that look the same on the line and need different lubricants on axes 5 and 6.
The wrist interval has its own quirk too: the oil on axes 5 and 6 is changed for the first time at 4,000 h or after one year, and every 5 years after that. That first change is the one most often lost sight of. On a robot with an incomplete history, there is not always a record of whether it was done, or with which oil. If there is no record, we treat it as outstanding.
IRB 6400 with S4: grease where many expect oil
The M96 manual for the IRB 6400 with S4 splits the robot into two lubricants and two rhythms:
- Axes 1, 2, 3 and 6: grease, not oil, changed every 5 years. In press-tending applications, the manual brings axis 1 down to 12,000 h or 3 years.
- Axes 4 and 5: ISO 320 oil, changed at 12,000 h or 3 years.
Applying an “oil change on every gearbox” plan to this robot is a fundamental mistake, and not just on lubricant: on intervals too. These figures are also specific to the IRB 6400 with S4. If your 6400 runs on a different cabinet, the plan comes from its own manual, not this one.
IRB 4400 with S4: “for life” does not mean “nothing to do”
On the IRB 4400 with S4 (manual M94A), the gearboxes have no scheduled oil change. That does not leave the manipulator without a plan. What is scheduled:
- The gas spring of the balancing system, at 12,000 h.
- The measurement system battery, at 36 months.
On condition, the manual adds the signal cabling in the upper arm and the axis 1 mechanical stop, which is replaced if bent. The gas spring deserves particular attention: if it loses force, the weight it used to compensate ends up being carried by the motor and gearbox of that axis, and that does not show up in any lubrication plan.
The measurement system battery exists on S4 and S4C too
People tend to associate the battery that holds the revolution counters with modern controllers, but it was already there in the S4/S4C era. Depending on the robot, either the 6-cell nickel-cadmium battery 4944 026-4 or the 3-cell lithium battery 3HAB 9999-1 was used.
As a rough guide of our own, taken from our catalogue rather than from the manufacturer, the NiCd lasts around 3 years and the lithium up to 5. Where the robot's manual sets an interval, the manual takes precedence: on the IRB 4400 with S4, the M94A schedules it at 36 months. What happens when it runs flat and how to recover the counters is covered in ABB revolution counter not updated.
Cabinet: all-in-one on S4 and S4C, its own manual on S4C+
In the S4 and S4C manuals, the cabinet plan sits inside the robot manual, in the same document. Intervals are laid out in columns such as “twice a year / once a year / 4000h / 12000h / 5y / 20000h”, and the S4 manuals are scans. You cannot search the text, and a cabinet row is easily skipped if you read it thinking only about the manipulator.
On the S4C+ (M2000), the cabinet has its own procedures manual, 3HAC021333-004. Its intervals are:
- Cabinet inspection: every 6 months.
- Air filter in the front panel: every 4,000 h or 24 months.
- Backup battery: every 12,000 h or 36 months.
- Drive system and computer system fans: every 36 months.
- CMOS battery on the main computer: every 72 months.
These intervals belong to the S4C+. Do not carry them over to an S4 or an S4C: for those cabinets, the plan is the one in the robot manual. For the same reason, a plan written for IRC5 or OmniCore does not apply here either; those are different controllers with their own documentation.
What we check first on an ABB S4, S4C or S4C+
In our inspections of these robots, before touching a gearbox we establish which generation each robot and each cabinet belongs to, which manual it has been maintained to, which lubricant each axis carries and when it was last changed. From that we build the plan robot by robot, not by family. We cover ABB from S4 to OmniCore as part of our ABB robot maintenance, and the resulting schedule goes into the site's preventive maintenance plan.
If you have ABB robots from that era still in production, run a simple check: find the manual being used for their maintenance and see whether its version matches the generation of the robot and the cabinet. If the manual belongs to another generation, the lubricants and intervals being applied are most likely not the right ones either.