Cat 303ECR Rubber Tracks & Parts

The CAT 303E CR runs a 300x52.5Wx84 track: 300 mm across the tread, 52.5 mm between links, 84 links around. Cut for digging, trenching, backfill and tight-quarters work and shipped free to the lower 48.

What the numbers mean on a CAT 303E CR

  • 300x52.5Wx84 — 300 mm tread width (about 12"), 52.5 mm pitch, 84 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 CAT 303E CR

Size gets the track on the machine; tread decides how it works and how long it lasts. What we stock for this one:

  • Staggered Block — mixed dirt and gravel. Block stability with better cleanout than a straight block

Undercarriage parts for the CAT 303E CR

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:

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 300x52.5Wx84 shows up on machines from several makers. If you run any of these alongside the CAT 303E CR, it is the same belt:

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.

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Track sizes

Heavy-Duty Rubber Tracks for 303E CR

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  • 300x52.5Wx84 Block Rubber Track
    CAT 303E CR 300x52.5Wx84 300x52.5Wx84
    • Heavy Duty | 300x52.5Wx84
    $1,149.00$999.00

    In stock

    Add to quote
  • 300x52.5Nx84 Directional Rubber Track
    CAT 303E CR 300x52.5Nx84 300x52.5Nx84
    • Heavy Duty | 300x52.5Nx84
    $981.50$943.75

    In stock

    Add to quote
  • 300x52.5Wx84 Bridgestone Rubber Track | MX
    CAT 303E CR 300x52.5Wx84
    • Bridgestone | 300x52.5Wx84

    Request quote

    Add to quote

  • 100% Virgin Rubber

    Engineered to resist chunking, tearing, and cutting in harsh, abrasive environments.

  • Continuous Steel Cords

    Jointless internal cable architecture eliminates structural weak points and maximizes overall tensile strength.

  • Drop-Forged Links

    Precision heat-treated guide lugs ensure exact sprocket engagement and prevent de-tracking under heavy side-loads.

  • Corrosion Resistant

    The internal steel framework is fully encapsulated to prevent oxidation, rust, and moisture penetration.

  • Reinforced Sidewalls

    Extra-thick vulcanized rubber and tapered edge profiles protect against curb slashing and lateral impacts from jobsite debris.

  • Low-Vibration Tread

    Optimized lug spacing and pitch geometry absorb shock, reducing undercarriage wear and minimizing cabin vibration.

Cat 303ECR Rubber Tracks & Parts fitment data

Verified-fit rubber tracks and undercarriage parts for the Cat 303ECR. Confirm size and tread before ordering.

Frequently Asked Questions

What size rubber tracks fit a Cat 303ECR?
The Cat 303ECR can use 300x52.5x84 rubber tracks. Match the full size on the track you are replacing before you order. If your machine has more than one track setup, choose the width and guide style that matches the track currently on the machine.