How to Inspect Pins, Bushings and Boom Welds on a Used Excavator

Engine smoke and track wear get most of the attention, but pins, bushings and boom welds often decide how soon a used excavator needs downtime after it arrives. These parts are expensive to rebuild and easy to miss on a washed machine. Use this checklist on a yard walk-around or when you review an inspection video.

1. Watch for play at the main pivots

Have the operator set the bucket on the ground, then slightly raise and lower the boom and crowd the arm. Look at the boom foot, boom-to-arm pin and bucket linkage. Visible movement, a dull knock, or grease that looks metallic means the pin or bushing is worn. Measure or at least photograph the gap so you can discuss it with the seller.

2. Check grease condition and pin caps

Dry pins with rust at the ends have not been greased regularly. Missing or broken pin retaining bolts and lock plates are a safety issue, not a cosmetic one. Fresh, clean grease right before a sale can hide wear—wipe a little away and look at the color and whether metal flakes are present.

3. Inspect boom and arm welds

Study the boom foot, the top of the boom near the cylinder brackets, the arm cylinder mount and the sides of the arm. Hairline cracks, stop-drill holes, or uneven new weld beads are signs of previous repairs. A tidy repair can be acceptable if it is disclosed; a rushed cover-up should change the price or the machine you choose.

4. Do not skip the swing frame and bucket

Cracks also appear around the swing bearing boss and on the bucket side plates or hinge. A cracked bucket is cheaper to fix than a cracked boom, but it still tells you how hard the machine worked. Ask for photos taken in daylight, not only in a dark workshop.

5. Price the repair before you commit

Replacing a set of boom and arm pins and bushings, or repairing a structural crack, can take days in a workshop and add a meaningful cost after import. If the rest of the machine is sound, negotiate that cost into the FOB price or ask the yard to repair and re-video before the balance payment. Share the stock number and we can help you review the pin and weld areas on the unit you are considering.

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YC Used Machinery / Shanghai Yongcheng Used Machinery
No.68 Qinggao Road, Fengxian District, Shanghai, China
WhatsApp: +86 166 8175 4290 · Email: vangher43@gmail.com
Website: https://selldigger.com
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