Where Can I Buy Caterpillar Parts Online?

Buying Caterpillar parts online works for the majority of CAT wear and maintenance needs, often at meaningful savings over the dealer counter. The trade-off is knowing where OEM still matters. Filters, bucket teeth, cutting edges, undercarriage, glass, and hydraulic components are all well-served by aftermarket. Emissions, ECM programming, and active-warranty scenarios stay OEM.

At a Glance

• Aftermarket-safe categories: bucket teeth, cutting edges, undercarriage, filters, glass, mirrors, seals, hoses, belts, electrical
• Stay OEM for: Tier 4 DPF and DEF emissions parts, ECM programming, active warranty work
• Look up parts by: full serial number (not just model). The 320/330/336 excavator families especially have multiple production runs with revised part numbers
• Shipping beats the dealer counter: most online aftermarket suppliers ship same-day, compared to 3 to 10 day dealer lead times
• Savings range: 30 to 70 percent vs. dealer depending on category

Can I Really Buy Caterpillar Parts Online, or Is the Dealer the Only Option?

The Caterpillar dealer network (CAT Parts Store, wheelercat.com, wagnerequipment.com, warrencat.com) dominates the first page of search results, which creates the impression that parts only flow through dealers. The reality is different. Aftermarket suppliers carry the vast majority of CAT wear and maintenance parts at lower prices with same-day shipping.

The dealer retains three structural advantages: ECM programming access, Tier 4 final emissions parts traceability, and active-warranty documentation. Outside those three, aftermarket online is faster and cheaper for identical functional parts. According to Caterpillar's own service publications, standard maintenance intervals are consistent across OEM and quality aftermarket parts.

Which CAT Parts Are Safe to Buy Aftermarket?

The aftermarket-safe list is long and covers most typical service scenarios:

• Wear parts: bucket teeth, cutting edges, side cutters, pin-and-lock hardware, adapter plates
• Undercarriage: track shoes, track chains, rollers, idlers, sprockets
• Filters: engine oil, fuel, hydraulic, return, air, cabin
• Hydraulic: hoses, cylinder seal kits, O-rings, pilot valves
• Glass: windshields, side glass, rear glass, skylights, door seals
• Mirrors: non-heated side mirrors for most skid steer, excavator, and wheel loader platforms
• Electrical: alternators, starters, batteries, lights, switches

Browse Caterpillar parts to see current stock.

Which CAT Parts Should I Always Buy OEM?

A narrow list, but important:

• Tier 4 final emissions components (DPF, DEF dosers, NOx sensors) on 2014-and-newer machines
• ECM modules and proprietary sensors requiring dealer programming
• Active-warranty repairs where Caterpillar requires OEM for coverage
• Parts with regulatory traceability requirements (safety-critical items)

Outside these, aftermarket is the practical choice. Our parts specialists frequently recommend aftermarket for all routine service intervals and OEM for Tier 4 emissions work specifically.

How Do I Find the Right CAT Part Number for My Machine?

The chain is: model, then serial number, then part number. CAT's serial number is the authoritative lookup key. Cross-reference the part number against the supplier's listed fitment range before ordering.

CAT serial numbers are 8 to 10 characters depending on machine generation, typically stamped on a data plate near the operator station or on the main frame. Pre-2001 serials are shorter; post-2001 machines follow the 17-character PIN standard where the 10th character encodes the model year (A = 2010, L = 2020, S = 2025, skipping I, O, and Q).

What's the Difference Between CAT Branded, CAT Reman, and Aftermarket?

Three tiers, each with a place.

• CAT Branded (genuine): new OEM in a CAT box. Full warranty, full price. Use for active-warranty scenarios
• CAT Reman: remanufactured by Caterpillar from a core, rebuilt to OEM spec, carries a Cat Reman warranty. Cost is typically 60 to 80 percent of new. Good option for major components (engines, pumps, alternators)
• Aftermarket: built by third-party manufacturers to match or exceed OEM specifications. Cost is typically 30 to 60 percent of new OEM. Best for wear and maintenance parts

Based on our catalog data, the most common customer pattern is OEM for one or two critical components, CAT Reman for mid-tier items, and aftermarket for everything else. That mix typically delivers the best cost-to-coverage ratio.

How Do I Use My CAT Serial Number to Order Parts?

Step-by-step:

1. Find the serial plate (cab pillar, frame, or engine block location depending on machine)
2. Record the full serial — letters and numbers both matter
3. Identify the base model (e.g., 320D, 336F, 259D3)
4. Search the aftermarket supplier with the serial and base model
5. Confirm the supplier's fitment range covers your serial
6. Order with the cross-referenced OEM number for reference in your records

For fitment verification on non-standard orders, email sales@partsonline.com with the serial and part description.

How Can I Tell If an Aftermarket CAT Supplier Is Legitimate?

Five practical markers:

• They publish the OEM cross-reference number directly on the product listing
• They specify which CAT models and serial ranges the part fits
• They offer a genuine return policy without restocking games
• They stock in a North American warehouse (not drop-shipping overseas)
• They answer phone and email questions before the sale

If a supplier will not tell you which OEM number their part replaces, walk away.

How Much Do I Actually Save Buying CAT Parts Online?

Savings vary by category:

• Filters: 60 to 75 percent below dealer
• Bucket teeth and cutting edges: 40 to 60 percent below dealer
• Hydraulic hose and seals: 40 to 60 percent below dealer
• Glass: 30 to 50 percent below dealer
• Electrical (alternators, starters): 40 to 70 percent below dealer (especially for quality remanufactured)

Over the annual maintenance cost of a working CAT fleet, aftermarket saves meaningful amounts per machine per year, compounding across fleet size.

What Do I Do If the Part I Ordered Is Wrong?

Contact the supplier, reference the order number and serial number, and confirm the intended fitment. Legitimate aftermarket suppliers either ship the correct part or issue a refund. The most common cause of wrong-fit returns is serial-range variation within a single model — a 320D built in 2008 may take different parts than a 320D built in 2012.

Which Aftermarket Brands Are Trustworthy for CAT Wear Parts?

Look for published OEM specifications on the listing, clear fitment ranges, and established North American distribution. Quality aftermarket manufacturers often supply the same factories that supply Caterpillar directly, which is why the physical parts are often identical. Consult a certified mechanic for complex diagnostics before ordering high-value replacement components.

Frequently Asked Questions

Where can I find a Caterpillar parts catalog online?

Caterpillar maintains an official parts catalog through the Cat Parts Store and dealer portals. Aftermarket suppliers publish parallel cross-referenced catalogs that index to the same OEM part numbers, which is often the faster path for non-dealer customers.

Can I look up Cat parts by serial number online?

Yes. Most aftermarket supplier sites allow serial-based lookup. Cat's own store supports it for dealer customers through the Cat Parts Store login.

Where can I find Cat parts diagrams?

Exploded-view diagrams are available through the Cat Parts Store and through aftermarket supplier listings for major assemblies. Diagrams help most with hydraulic and undercarriage rebuilds.

Are Cat parts available near me?

Local availability depends on your region and the part category. For fast, consistent stock, online aftermarket suppliers with North American warehouses typically ship the next business day across the continent.

What is the difference between Cat parts for BMW and Cat parts for Caterpillar?

"Cat parts BMW" refers to catalytic converter parts for BMW vehicles and has nothing to do with Caterpillar heavy equipment. This guide covers Caterpillar construction and earthmoving equipment parts only.

Where do I log in to order Cat parts?

Caterpillar's dealer and fleet customers log in to parts.cat.com. Retail customers and smaller operators often order directly from aftermarket suppliers like partsonline.com, which does not require a login for browsing or ordering.

Shop Caterpillar parts, or browse by equipment type: excavator parts and skid steer parts. For fitment verification on your specific CAT machine, email sales@partsonline.com with the serial number.