280-2357 Gear for Caterpillar Mini Excavator 303.5C 303.5D 303.5E | Durable Replacement Part
The 280-2357 gear is a planetary final drive reduction gear for Caterpillar mini excavators 303.5C/303.5D/303.5E (also fits 303C CR/303.5CR/303.5E2/304/304E2). It works in the travel motor gearbox to reduce speed, amplify torque, and drive track movement smoothly for landscaping, utility, and small-scale construction tasks.
Key Features
· OEM-Matched Precision: 20CrMnTi alloy steel, precision-machined teeth, exact pitch/diameter—no modification needed for Cat models.
· Durable Construction: Carburized tooth surface (58–62 HRC) for wear resistance; shot-peened for fatigue strength.
· High Torque Capacity: Optimized for 1,800 N·m max torque; low backlash (<0.05mm) for stable track operation.
· Plug-and-Play Installation: Direct fit into final drive assembly; 45-minute replacement with basic hand tools.
· Long Service Life: 8,000+ hours lifespan; 100% tested for tooth profile, hardness, and dimensional accuracy.
Compatible Equipment
· Mini Excavators: Caterpillar 303.5C, 303.5D, 303.5E, 303C CR, 303.5CR, 303.5E2, 304, 304E2.
· Interchangeable Part Numbers: 280-2357, 2802357.
Thank you for choosing SPARKLING MACHINERY for your gear needs. The 280-2357 final drive gear is critical for consistent track performance in Cat 303.5-series mini excavators, ensuring reliable operation in tight spaces and tough terrains. Our gears meet ISO 9001 and Cat OEM standards, backed by a 12-month warranty and technical support for installation/troubleshooting.
The SPARKLING MACHINERY NEW 280-2357 Gear Photo:
Why Choose the SPARKLING 280-2357 Gear?
- OEM-Grade Fit: Matches original tooth count, module, and mounting position—restores 99%+ drive system efficiency.
- Superior Durability: 20CrMnTi steel with carburizing treatment reduces wear/fatigue failure by 65% vs. generic gears.
- Reduced Downtime: Plug-and-play design cuts replacement time; 100% inspected for cracks via magnetic particle testing.
- Cost-Effective: 40% lower price than OEM with same quality; 12-month warranty covers manufacturing defects.
- Certified Quality: CE/RoHS compliant; each unit passes tooth contact pattern and backlash testing.
| PART NUMBER | PART NAME | |
| 1 | 310-9356 | CONTROL GP-TRANSMISSION |
| 2 | 246-2671 | SWITCH AS-MULTIFUNCTION |
| 3 | AT159811 | SWITCH |
| 4 | AT393721 | SWITCH |
| 5 | RE500539 | FAN DRIVE |
| 6 | ZTAM-00509 | JOINT ASSY-UNIVERSAL |
| 7 | 21M9-50900 | LAMP ASSY-COMBI LH |
| 8 | 3E-9362 | RELAY |
| 9 | 146-9439 | RELAY |
| 10 | 261-2207 | GP-Transmission Controll |
About SPARKLING MACHINERY:
- Founded in 2013, SPARKLING focuses on high-quality excavator parts across hydraulics, undercarriage, engines and electrical systems. We prioritize stability, precision and continuous service, offering worldwide distribution, tailored solutions and strict QC to help customers reduce cost and increase uptime.

Get In Touch:
- Replace your failing ECU confidently. Contact SPARKLING for pricing, lead time, and technical support — restore optimal machine control quickly and reliably.
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📦 Packing
1. Packaging methods: Carton box + Wooden case/Pallet + Anti-rust treatment
2. Export-standard packaging to ensure safety during transportation
3. Custom packaging available upon request
4. Dimensions and weight can be provided for freight calculation



🚚 Shipping
1. Available shipping methods: Sea freight, Air freight, Express delivery (DHL, UPS, FedEx, etc.)
2. LCL (Less than Container Load) and FCL (Full Container Load) options are supported
3. For Russian clients, we can introduce the forwarder agent to you
4. Delivery time: Ships within 1-3 working days after payment (for items in stock)
💳 Payment
1. Accepted methods: T/T, Bank Transfer, PayPal, Alipay, WeChat Pay, Western Union
2. Deposit + balance payment available for large or custom orders
3. Flexible payment options—feel free to contact us for details
📌 Frequently Asked Questions (FAQs)
Q: Which excavator models is this part compatible with?
A: This product is compatible with major brands such as CAT, KOMATSU, HITACHI, and more. Custom specifications are also available.
Q: How can I make sure I’m selecting the correct part?
A: You can send us a photo of the old part, part number, or your excavator model, and we will help you confirm the right match.
Q: Is there a warranty for this product?
A: Yes, we offer a 6-month quality guarantee under normal use.
Get a free quote
We are committed to producing the highest quality products at the most competitive prices. Therefore, we sincerely invite all interested companies to contact us for more information.
Sparkling Machinery Co.,Ltd
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Whatsapp: +8613609010879