The Pin Fits. The Bore Does Not.
Worn excavator bucket, boom, stick and linkage bores can often be restored by machining the damaged bore back to true geometry and fitting the correct bushing, sleeve or pin arrangement rather than replacing the entire assembly.
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- 337-837-2314
Worn excavator bucket, boom, stick and linkage bores can often be restored by machining the damaged bore back to true geometry and fitting the correct bushing, sleeve or pin arrangement rather than replacing the entire assembly.
The pin has movement, the bushing will not stay tight, the bore has gone oval, or a replacement pin still leaves slop. On excavators and similar equipment, the expensive part is often the bucket, boom, stick or linkage itself; the wear is concentrated at the pin-and-bushing interface.
What to do
- 01
Identify every bore that belongs to the same pivot
A pivot is an alignment problem, not just a diameter problem. Photograph both sides of the lug or linkage and note whether two or more bores have to share one axis. That determines whether ordinary boring or a line-boring setup is required.
- 02
Measure the pin and the worn bore separately
Do not assume the pin is still nominal. A worn pin inside a worn bore can hide how much material has actually been lost. The repair plan has to decide which component returns to standard and which component is made to suit.
- 03
Decide whether the repair returns to an OEM-size bushing
When enough material remains, the preferred outcome is usually a true, round bore that accepts a serviceable bushing or sleeve. If the geometry or wall thickness makes that impractical, the pin-and-bushing set may need to be made around the repaired size.
- 04
Machine the bores on one axis where alignment matters
Multiple pivot bores are line bored from a common bar so alignment is built into the cut. Correct diameter without correct alignment still creates binding, uneven wear and short bushing life.
- 05
Check the mating pin, bushings and grease path before reassembly
A repaired bore can be damaged quickly by a worn pin, incorrect bushing fit or blocked lubrication path. The whole pivot should be treated as one wear system rather than three unrelated parts.
Questions People Ask
Can an oval excavator pin bore be repaired?
- Often, yes. The worn bore is machined back to true geometry and the repair is finished around the required pin-and-bushing fit. If paired bores have to remain aligned, they are line bored on a common axis.
Should the pin and bushings be replaced at the same time?
- They should at least be inspected as part of the same repair. A new or restored bore running on a badly worn pin can recreate looseness quickly, and Machine Tech can machine replacement pins, bushings or sleeves when the repair calls for them.
Do I need to bring the entire excavator?
- No. Machine Tech is describing shop-based line boring, so the removable bucket, boom, stick, linkage or other component is the relevant piece. Send photos and dimensions first so the shop can confirm handling.
Send us the part.
337-837-2314 — or send photographs and we will tell you what we can do.