Heavy Equipment & Parts

Two Departments, One Aisle

This category runs in two directions. The first half is trailer parts — axles, electric brakes, couplers, jacks, springs and lighting, the stuff that wears out or gets bent and has to be replaced before the trailer goes back to work. The second half is heavy equipment and attachments — excavator buckets, wheel loader buckets, solid skid steer tires, industrial engines, snow pushers and hoop buildings. Different buyers, different questions. Both are below.

Trailer Parts: Axles, Brakes, Couplers, Lighting

Axles and suspension

Axles are sold by capacity, and the capacity you need is set by the trailer's GVWR, not by what looks stout. Tandem 3,500 lb axles give 7,000 lb of capacity, the most common configuration on the market; step up to 5,200, 6,000 or 7,000 lb for dump, equipment and car hauler work. Two numbers must match on a replacement: hub face to hub face and spring center to spring center. Get those wrong and nothing bolts up. Bolt pattern follows capacity — 5-on-4.5" on most 3,500 lb hubs, 6-on-5.5" on 5,200 and 6,000 lb, 8-on-6.5" on 7,000 lb and up. Our trailer axle capacity chart lays the ratings out side by side.

Electric brakes and controllers

Brake assembly size tracks axle rating: 10" x 2-1/4" on 3,500 lb axles, 12" x 2" on 5,200 through 7,000 lb, and 12-1/4" x 3-3/8" on 8,000 lb and up. Brakes sell in left/right pairs because magnet arm and shoe geometry are handed. Any trailer with electric brakes also needs an in-cab controller and a working breakaway switch with a charged battery. Requirements are written at the state level and thresholds vary — many states start in the 3,000 to 4,500 lb GVWR range. Check trailer brake laws by state before crossing a line.

Couplers, gooseneck balls and pintles

The ball size tells you the fit; the stamping tells you the capacity. A 2" ball coupler is common up to roughly 7,000–10,000 lb depending on the part. A 2-5/16" bumper-pull coupler is typically rated 10,000, 14,000 or 21,000 lb gross trailer weight; gooseneck couplers running the same ball are usually 25,000–30,000 lb. Pintle and lunette ring combinations cover the heaviest end, commonly 10,000 to 60,000 lb, and tolerate rough-ground articulation better than a ball. Read the stamped rating on the part.

Jacks and lighting

Swivel tongue jacks are sold by static capacity — generally 2,000, 5,000 or 7,000 lb — with drop-leg versions saving cranks on tall couplers. Submersible LED kits are the default replacement for anything dunked at a boat ramp: sealed housings, DOT stop/turn/tail, 12V. Ground the trailer properly to the frame and most "bad light" calls disappear.

Heavy Equipment and Attachments

Excavator buckets are the volume item: 20" and 24" trenching buckets for the 12–18 ton class (Cat 315/316, Komatsu PC160/PC170, Kobelco 160, Hyundai 160), 36" tooth buckets on 45 mm pins for the same class, and wider general-purpose buckets as machine weight climbs. Tilt and ditching buckets run 60" to 84" without teeth — grading tools, not digging tools, where the hydraulic tilt earns its money on ditch and shoulder work.

Wheel loader buckets are rated in cubic yards rather than inches, usually 1.0 to 4.0 cy. A 4-in-1 bucket splits like a clamshell so one attachment digs, dozes, grapples and dumps — more money, more dead weight, one less attachment to haul. Solid skid steer tires in 10-16.5 and 12-16.5 are the answer on demolition and scrap yards where pneumatics puncture weekly. Also here: industrial diesel engines for repower work on compactors, chippers, pumps and gensets, plus fabric hoop buildings from 40x80 up, on double-truss frames with heavy woven covers.

How to Choose Trailer Parts and Attachments

• Start with the rating plate, not the tape measure. Trailer GVWR sets axle and brake capacity; machine weight and pin dimensions set bucket fitment.
• Measure axles twice. Hub face to hub face and spring center to spring center, written down, before you order.
• Match capacity across the chain. A 7,000 lb coupler on a 14,000 lb trailer is a failure waiting to happen — see GVWR, GAWR, payload and tongue weight explained.
• For buckets, get three numbers. Pin diameter, ear width and pin-to-pin spacing. Machine model alone is not enough.
• Buy brakes in pairs. One new side leaves mismatched shoe wear and a trailer that pulls under braking.
• Check the hydraulics. A tilt bucket or 4-in-1 needs an auxiliary circuit already plumbed.

Matching Attachments to Machine Class

Pin size is the fastest sort. Mini excavators in the 1–4 ton range typically run 30–40 mm pins and 12" to 30" buckets. The 12–18 ton class commonly uses 45–50 mm pins with buckets from 18" to 42". Above 20 tons, pins jump to 65 mm and beyond and buckets run 36" to 60". Quick couplers change the geometry entirely — a machine with a hydraulic coupler needs a bucket built for that coupler's ear spacing, not the bare machine's. Send us make, model, year and coupler type and we confirm fit before shipping.

Delivery & Buying Online

We ship parts and attachments nationwide to the lower 48. Small parts go ground; axles, buckets, engines and building packages go freight, quoted flat-rate up front so the number you approve is the number you pay. Everything carries our 30-day guarantee. Tell us the ZIP and whether you have a forklift or dock.

Related Categories

Browse utility trailers if you are replacing axles on a light hauler, dump trailers and equipment trailers for heavier 7,000 lb axle builds, or gooseneck trailers when a 2-5/16" gooseneck coupler goes under a load. Hauling the attachments sold here usually means a tilt deck trailer.