How to Identify Genuine OEM Excavator Parts vs Aftermarket Imitations

When you’re repairing or maintaining an excavator, choosing the right parts comes down to one question:

Am I getting a genuine OEM part, or a cheap aftermarket imitation?

That question matters because the difference between the two is HUGE. A genuine OEM component will last longer, fit perfectly, protect your machine, and deliver the performance the manufacturer intended. A bad aftermarket imitation can ruin an engine, damage a final drive, or create safety problems on site.

This blog gives you a practical, field-tested guide to spotting the real thing—and avoiding the fakes.

Let’s get into it.

1. What Is an OEM Part? (Quick Overview)

OEM = Original Equipment Manufacturer.

These are parts:

• built by the same company that made the machine or its core components

• produced under the exact factory specifications

• tested under strict standards

• certified for performance and durability

Examples:

• Volvo Penta engines for Volvo excavators

• Mitsubishi engines for some CAT and Komatsu models

• Kawasaki and Nabtesco travel motors

• Bosch Rexroth hydraulic pumps

OEM is the gold standard.

2. What Is an Aftermarket Part?

Aftermarket parts are built by independent companies.

There are three categories:

A-Grade Aftermarket (High Quality)

Well-known brands like Berco or ESCO.These can sometimes exceed OEM quality.

B-Grade Aftermarket (Medium Quality)

Reliable but not perfect.Good for budget-sensitive operations.

C-Grade Aftermarket (Low Quality / Imitations)

Cheap metal. Poor tolerances.These are the ones that destroy machines.

Your goal is to avoid C-grade imitations at all costs.

3. Why It Matters: OEM vs Aftermarket Failure Risks

Here’s what usually goes wrong with low-quality aftermarket imitations:

1. Wrong tolerances

The part may fit, but not properly—causing stress, leaks, or misalignment.

2. Weak materials

Cheaper metals = quicker wear = expensive failures.

3. No consistency

Two parts from the same supplier may not match.

4. Shorter lifespan

A component that should last 4,000 hours may fail at 600.

5. No real warranty

Or fine print that makes claims impossible.

6. Bad imitations can damage OEM components

Example: cheap sprockets destroying chains.

OEM parts prevent these risks.

4. How to Identify Genuine OEM Parts (The Practical Checklist)

Below are the 9 most reliable ways to check whether a part is truly OEM.

1. OEM Part Number Verification

Every OEM part has an exact part number.

Examples:

• Volvo: VOE ########

• Komatsu: 2###-##-#####

• Hyundai: ####-####L

• CAT: *******

Ask the seller for:✔ the exact number✔ photos of the number on the part✔ compatibility list

If the answer is vague—it's not OEM.

2. Check for OEM Branding, Stamping, or Casting Marks

OEM parts include markings such as:

• logos (CAT, Komatsu, Volvo)

• engraved numbers

• cast-in symbols

• QR codes

• serial numbers

• date codes

If the part has:

• no markings

• painted-over logos

• or stickers instead of stamps

…it is almost certainly aftermarket.

3. Compare the Weight (Fast and Easy Trick)

OEM parts often weigh more because they use stronger alloys.

Example:

• a genuine Komatsu bucket link weighs noticeably more

• a real OEM bushing has a denser metal composition

Cheap aftermarket parts feel light and hollow.

4. Look at the Machining Quality

OEM machining is precise:

• smooth edges

• clean tolerances

• consistent finishes

• no burrs

• uniform alignment

Aftermarket imitations show:

• rough edges

• uneven machining

• sloppy welds

• scratches

• inconsistent surfaces

Your eyes can spot the difference instantly.

5. Packaging Matters

OEM parts come in:

• branded boxes

• heat-sealed bags

• foam or protection wrap

• labelled packaging

Counterfeiters often use:

• plain boxes

• unbranded plastic

• reused packaging

• hand-written labels

Packaging isn’t everything—but it’s a clue.

6. Check Price Against Market Average

If the price is:

• dramatically lower than OEM

• too good to be true

…it is not OEM.

Example:A Volvo final drive normally costs ±R85,000–R120,000 used OEM.If someone offers one for R25,000, it’s either:

• aftermarket

• broken

• stolen

• or misidentified

OEM parts NEVER sell at fake discount levels.

7. Ask for Supplier Documentation

A legitimate OEM supplier can provide:

• stock photos

• machine teardown records

• quality check notes

• test results (especially for final drives, pumps, motors)

• supplier invoices

If a supplier refuses to show proof—avoid.

8. Check the Fitment Quality

OEM parts fit:

• perfectly

• smoothly

• consistently

• with no forcing or adjusting

Aftermarket imitations can require:

• hammering

• grinding

• adjusting

• re-drilling

• filing

If a part doesn’t fit easily, it’s not OEM.

9. Buy Only from Reputable Sellers

The easiest way to ensure OEM is simple:

Buy from a supplier who only sells OEM used excavator parts—like Vikfin.

Reputable suppliers:

• dismantle machines themselves

• verify part numbers

• test components

• provide accurate condition reports

• offer guarantees

A trustworthy supplier is your best defense.

5. Real-World Examples of OEM vs Aftermarket Problems

Case 1: Aftermarket final drive failures

Cheap drives often fail in <500 hours due to weak bearings and poor seals.

Case 2: Undersized aftermarket pins & bushings

These cause immediate play in linkages—ruining booms and arms.

Case 3: Counterfeit sensors & electronics

Fake sensors send incorrect readings and damage ECU systems.

Case 4: Poorly machined sprockets

Misaligned tooth profiles damage the chain quickly.

Case 5: Low-grade seals in hydraulic pumps

Leads to overheating, inefficiency, and catastrophic pump failure.

OEM prevents all these.

6. Quick Comparison Chart

Feature	OEM Parts	Aftermarket Imitations
Material Quality	High	Low
Fitment	Perfect	Inconsistent
Lifespan	Long	Short
Risk of Failure	Very Low	High
Warranty	Strong	Weak/None
Compatibility	Guaranteed	Questionable
Cost	Higher	Lower
Overall Value	Excellent	Poor

7. Final Tips for South African Excavator Owners

South Africa has a flood of cheap imported aftermarket parts.Some are good.Many are outright dangerous.

Stick to these principles:

1. Always check OEM numbers.

2. Ask for proof.

3. Check the weight and machining.

4. Avoid “too cheap” deals.

5. Buy from reputable suppliers only.

And whenever possible, choose OEM—especially for:

• final drives

• hydraulic pumps

• travel motors

• swing motors

• engine components

• electronic sensors

• undercarriage parts

These components take massive loads. They’re not worth the risk.

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