Undercarriage & wear parts
Bucket pins and bushings: sizes, wear and replacement
Bushing removal is the hard half
Pins come out with a drift. Bushings do not. A worn bushing is press-fit into the boss and typically has to be pushed or drawn out, which means either a press or a threaded puller sized to the bore. On the machine, in the field, that usually means removing the bucket or the linkage — which is why bushing replacement is rarely a roadside job.
If the bushing is seized, cutting it out is the usual fallback. That carries a real risk: cutting into the boss itself turns a bushing replacement into a weld and line-bore job.
Line boring, and when it becomes unavoidable
When the boss bore is oval beyond the point where a new bushing will hold, the bore has to be restored — welded up and machined back to size. This is specialist work, priced by the bore, and it is the outcome that good greasing discipline avoids.
The economics are stark: a pin and bushing set costs a fraction of a line bore, and the only thing separating the two outcomes is whether the joint was greased on schedule.
Grease frequency, practically
Daily in abrasive or wet conditions, and after any immersion. The failure mode is not that grease runs out — it is that the joint goes ungreased long enough for grit to enter, and grit mixed with grease becomes a grinding paste. Over-greasing is far less damaging than under-greasing.
Bucket pins and bushings are cheap parts that cause expensive downtime. A worn pin does not just rattle — it wears the bushing, then the boss, and eventually the bucket needs welding rather than a new pin.
Pin sizes are nominal, not standardised
There is no universal pin size table. Pins are specified by diameter and length for a particular linkage, and "25mm pin" describes the diameter only — it says nothing about the length, the retention method, or the boss bore it fits. Always measure, or take the part number.
What wears, in order
- The pin — wears oval, usually first
- The bushing — wears as the pin oscillates in it
- The boss — the bore in the bucket or arm; once this is oval, a new pin and bushing will not fix the play
This order is why catching a worn pin early is cheap and catching it late is not.
Measuring a pin
- Diameter at several points along the length and at two perpendicular axes — a worn pin is oval and tapered
- Length overall
- Retention — snap ring, bolt, or pin-and-washer; these are not interchangeable
- Bushing bore if replacing both
Signs it is time to replace
- Visible play when you rock the bucket by hand
- Grease escaping immediately after greasing — the clearance is too large to hold it
- Oval or tapered pin visible after removal
- Any scoring in the boss bore — at this point replacing the pin alone is wasted money
The greasing point people miss
A pin that is greased regularly wears far more slowly. A pin that is not greased wears the bushing and then the boss — and the boss repair requires welding, not a part. The cheapest maintenance on the machine is a grease gun used on schedule.
Ordering pins and bushings
Send: machine make, model, serial number; pin diameter and length; retention type; photos of the pin and the boss. We confirm the part before quoting: alfrun@gmail.com
Before you order
Send machine make, model, serial number and a photo of the casting mark. We confirm the part number and fitment basis before any price discussion.
Confirming the part before you order
Measurements get you close. A serial number and a photograph of the casting mark confirm it. Here is exactly what we need, and why each item matters:
Trademark notice
Machine brand names and part numbers are used only to describe fitment and application. We are not an authorised dealer of any machine manufacturer.
Reviewed by Zhonglei M&E parts desk — export trading partner for undercarriage and wear parts. Last updated 2026-11-13.