Pins and bushings on the boom, arm, bucket linkage and bucket should be greased every 10 hours of work in normal conditions, every 8 hours in dust, water or continuous breaking, and at the end of the shift rather than the start so that fresh grease is pushed through while the joint is warm and the machine will stand until the next shift. Grease that is applied until old grease shows at the joint has flushed the bearing; grease applied until the fitting squeaks has done nothing. The interval matters less than the confirmation that new grease left the joint, because a blocked or forgotten fitting wears a pin out at the same rate as no grease at all.
How to confirm it
- Set the interval from the duty, and write it on the machine
Count running hours, then choose 10 hours for normal conditions, 8 hours in dust or water, and 4 to 6 hours for breaker work. Put the interval on a decal or in the cab where the operator sees it, because a schedule that lives only in the office is a schedule that gets skipped.
- Grease at the end of the shift
Move the grease routine to the end of the working day so the joints are warm and the machine will stand. This is the single most effective change you can make, and it costs nothing beyond moving the task.
- Pump slowly until fresh grease shows at the joint
Wipe each fitting before coupling the gun, then watch the joint rather than the gun. Fresh grease appearing at the seal is the confirmation that the old grease has been displaced. If nothing appears, stop and find out why rather than pumping harder.
- Clear or replace blocked fittings
Remove the fitting, clear the passage, and replace the fitting if it is damaged or flattened. A fitting that will not pass grease is the most common reason a joint appears greased and is not.
- Check joint play and listen for knock
At every service, take the load off each pin in turn and feel for movement, then work the function slowly and listen for a knock as the load reverses. Recording which joints have play builds the history that tells you when to plan a rebuild.
- Record the findings with the hours
Note the hours, the grease used and any joint with play. Pin and bushing wear is slow and steady, so a written record turns a surprise failure into a planned repair.
What to do about it
A joint with play but no knock: schedule the bushing and pin replacement, and shorten the interval for that position in the meantime. Greasing a loose joint helps, but it does not restore the bearing area that has already been lost.
A joint that knocks under load: replace the bushing and pin together rather than one of the two. A new pin in a worn bushing wears out at the rate of the worn bushing, and the pair is designed to work as a matched set.
Grease that will not enter any joint: clear or replace the fitting and confirm that grease appears at the joint before moving on, because a routine that is assumed to have worked is the same as one that was not done.
Worn or hogged bore in a casting: this needs line boring or weld-and-machine repair, which is a specialist job rather than a parts swap. Treat it as the consequence of the missed interval, and use it to set the interval for the rest of the fleet.
Parts you may need, by grade
| Part | Grades commonly quoted |
|---|---|
| Linkage pin | Genuine; OEM-quality. Diameter, length, retaining feature and hardness spec all have to match. |
| Bushing | Genuine; OEM-quality. Replace with the pin as a matched set. |
| Pin seal or dust seal | Genuine; OEM-quality. The cheapest item on the list and the one that decides joint life. |
| Grease fitting | Genuine; OEM-quality. Standard thread sizes, but confirm the angle and length on recessed positions. |
| Grease | Specified grade for the load and climate. Compatibility with the existing grease matters. |
Need the parts this covers?
Send the machine model, serial number and the part numbers you need. We confirm fitment before payment and state the grade of every line — genuine, OEM-quality or aftermarket.
Request a quoteFrequently asked
How often should I grease an excavator linkage?
Every 10 running hours in normal conditions, every 8 hours in dust or water, and every 4 to 6 hours for breaker work. The figure that matters is hours worked, not days elapsed, so a machine on double shifts needs the routine twice as often. Whatever interval you choose, confirm that fresh grease actually leaves the joint, because the interval is meaningless if the fitting is blocked.
What happens if I skip greasing for a while?
Nothing visible at first, which is why it gets skipped. Wear opens the clearance gradually, the joint begins to knock under load, and the wear then accelerates because a loose pin takes impact over a small area. Left long enough, the bore in the boom or arm wears, and the repair becomes line boring rather than a pin and bushing change.
Does more grease always mean longer joint life?
No. What matters is fresh grease reaching the bearing and displaced old grease leaving it. Pumping a sealed joint until the seal is forced out lets water and grit in from then on, which shortens life. Pump slowly, watch the joint, and stop when fresh grease appears.