Kubota U45S tracks and undercarriage, sized 400x72.5Wx74 (400 mm wide × 72.5 mm pitch × 74 links). Made for digging, trenching, backfill and tight-quarters work. Free freight, 24-month warranty.
What the numbers mean on a Kubota U45S
- 400x72.5Wx74 — 400 mm tread width (about 16"), 72.5 mm pitch, 74 links, wide guide lugs
Width is the tread face, pitch is the distance between drive lugs, and links is the count around the loop. All three have to match — a track one link off will not tension correctly no matter how close the width is.
Tread choice for the Kubota U45S
Size gets the track on the machine; tread decides how it works and how long it lasts. What we stock for this one:
- MX — mixed and hard surfaces. A durable general-duty excavator tread
Undercarriage parts for the Kubota U45S
Rollers, idlers and sprockets wear on the same clock as the track. Fitting new rubber over a hooked sprocket or a seized roller is the fastest way to lose the new track — check these while the tracks are off:
- Drive sprocket — SPRD411-14432
- Bottom roller — TRRD411-21703
- Carrier roller — RD411-22900, 4392416
Where more than one part number is listed, Kubota changed that component across serial ranges. Match the number stamped on the part you are replacing, or send us the machine serial and we will pick it.
How these wear
Excavator undercarriages load one side hard on slew and travel, so link cracking usually shows up before the tread wears out. Replace in pairs where you can: a new track running against a stretched one loads the drive unevenly and you will feel it in the steering.
Same track, other machines
Track size follows undercarriage geometry, not brand, so 400x72.5Wx74 shows up on machines from several makers. If you run any of these alongside the Kubota U45S, it is the same belt:
- Airman AX58
- Airman AX58MU
- Bobcat 337
- Bobcat 337D
- Bobcat 337G
- Bobcat 341
- Bobcat 341D
- Bobcat 341G
- Bobcat 435
- Bobcat 435ZHS-FASTTRACK
Not sure which you are running? Read the size off the inside of the old track, or call (850) 816-7898 and we will pull it off the machine record. The Track Finder works by make and model too.
