When buying spare parts, most people stop at the same point: genuine parts are expensive, aftermarket ones are cheap — does the difference really matter? There’s no one-sentence answer to this question. For some parts, using aftermarket is a reasonable saving; for others, a cheap part opens the door to a much more expensive breakdown within a few weeks.
In this guide we suggest making the decision not by the part’s price but by what happens if the part fails. We sort parts by risk level, explain the technical points to watch with filters, hydraulics and fasteners, and give a simple formula for calculating the real cost and a list of questions to ask when buying aftermarket.
Terms first: genuine, aftermarket and counterfeit aren’t the same thing
On the market these words are used interchangeably. Before you decide, be clear about what you are comparing with what:
- Genuine part: A part supplied under the machine manufacturer’s own part number, the one the machine was designed around. Its dimensions, material and performance values were worked out together with the machine.
- Aftermarket (equivalent) part: A part made by another manufacturer to the same dimensions and function. Aftermarket isn’t a quality level but a type of source: some are very close to genuine, others only match the outside dimensions.
- Counterfeit part: A part passed off as genuine, with copied branding or packaging. An aftermarket part is openly sold as aftermarket; a counterfeit pretends to be something it isn’t. Aftermarket is a legitimate option; counterfeit is not.
- Used (salvaged) part: A part removed from another machine. Because you can’t know its history, it is the highest-risk option for critical parts.
There is an in-between case too: for some parts, the supplier that makes the genuine part may also sell the same part under its own brand. In that case the difference is often just the packaging. But verify this by looking at the codes and markings on the part, not on the seller’s word.
The real question: what happens if the part fails?
When assessing a part, the first question to ask shouldn’t be “how much will I save?” but “what happens if this part fails?”. Depending on the answer, you can sort parts into four groups:
| Group | Example parts | If it fails | Approach |
|---|---|---|---|
| Safety-critical | High-pressure hydraulic hoses, attachment mounting pins, critical connecting bolts, brake and lifting system parts | People can be injured, loads can fall | Genuine, or a part with documented technical values |
| Causes knock-on damage | Engine oil, fuel, air and hydraulic filters; cylinder seals; hydraulic pumps and valves | Dirt and wear spread to the pump, valves and engine | Genuine, or aftermarket of proven quality |
| Wear parts | Tracks, rollers, drive sprockets, bushings, bucket teeth | Wear progresses gradually and can be monitored | Aftermarket with clear dimension and material information can be considered |
| Comfort and bodywork | Body panels, mirrors, seat covers, lamp lenses | Operating safety isn’t directly affected | Aftermarket is often a reasonable saving |
The same part can change group depending on the machine’s working conditions. On a machine working in a flat garden, a track roller is in the third group; on a machine working with heavy loads on sloping ground, a roller that suddenly seizes can make the track come off and turn into a safety problem.
Intensity of use also affects the decision. On a machine that works a few hundred hours a year, a short-lived part will rarely bother you; on a machine providing services from morning till night every day, every unexpected stoppage means lost income. The harder a machine works, the more a part’s reliability matters compared with its price.
Where cheap turns out expensive with filters
Filters look identical from the outside: same diameter, same thread, a similar canister. The difference is inside, where you can’t see it:
- Filtration fineness: The size of particle the filter holds back. A coarser element lets bigger particles through to the engine or hydraulic system.
- Element surface area: The total area of the pleated filter paper. If the area is small, the filter clogs sooner.
- Bypass valve: The valve that opens to keep the oil flowing when the filter clogs. If its opening value isn’t right, the filter is taken out of action early and the oil circulates unfiltered.
- Seal and anti-drainback valve: A poor-quality seal lets dust get past an air filter, or oil leak from an oil filter.
Let’s be honest — a filter is the cheapest protection item on a machine, while the engine and hydraulic pump are the most expensive items. The price of a small saving on a filter comes back as permanent wear on the internal parts. We explain which filter to change when in detail in our guide to filters on construction machines.
Hydraulic parts: pressure doesn’t forgive mistakes
The hydraulic system works under high pressure, so with hydraulic parts it isn’t enough to say “the size fits”.
Hoses: A hose’s strength comes not from its appearance but from its pressure class, its inner layer construction and correctly crimped fittings. A hose with too low a pressure class may work without problems for the first few days and then burst a few weeks later, and the jet of oil can cause serious injuries. We explain choosing hoses and the causes of bursts in our hydraulic hose guide.
Seals: Cylinder seals are chosen by material, hardness and dimensional tolerance. A seal of the wrong material hardens or tears quickly under temperature and pressure; the leak comes back, and the dirt that gets in starts new damage too.
Pumps and valves: These are parts machined to fine tolerances. An inefficient pump slows the machine down, heats the oil and increases fuel consumption. In this group, always be clear about where the part comes from; you can see model-compatible parts on our hydraulic parts page.
Bolts and pins: small parts, big consequences
Because bolts are cheap, they are the parts people most readily “make do” with; yet at some points they are what holds the machine together.
- Property class: Steel bolts usually have property class markings such as 8.8 or 10.9 on their heads. Replacing a bolt removed from a critical joint with a lower-class bolt can cause the joint to loosen or snap under load.
- Length and thread pitch: Two bolts of the same diameter can have different thread pitches. A bolt forced in strips the thread in its hole.
- Pins: Pivot pins are usually surface-hardened parts. A pin made of soft material wears quickly and makes the much more expensive pin bore go oval.
- Washers, shims and nuts: Spring washers and shims keep the joint tight and preserve its clearance; they shouldn’t be left off on the grounds that “they don’t matter anyway”.
You can find model-compatible bolts, pins, nuts, washers and shims on the bolts and fasteners page. For tightening torques, go by the values in the operator’s manual.
Real cost: beyond the price tag
Deciding on a part by its price tag is misleading. For a more accurate comparison, use this formula:
Real cost = Part price + Labour + Downtime cost + (Probability of failure × Possible damage)
Example (sample figures; calculate with your own prices and times): Say a genuine filter costs 100 units and its aftermarket equivalent 60 units. Each change costs you 40 units in labour and downtime. If the aftermarket filter clogs in half the time of the genuine one, you will do two changes with the aftermarket filter in the period in which you would do one with the genuine filter:
- Genuine: 100 + 40 = 140 units
- Aftermarket: 2 × (60 + 40) = 200 units
This calculation doesn’t yet include the damage the aftermarket filter could do to the engine or hydraulic system. The reverse is also possible: with a body part whose life is equal to the genuine one, aftermarket really does save money, because neither the replacement frequency nor the risk changes.
Calculating downtime cost
Downtime is the item most often forgotten in the formula. To find your own figure, answer these questions: when the machine stops, what is the value of the work that can’t be done that day, are workers standing idle, do you need to hire a replacement machine? Downtime cost = (Daily work lost + Idle labour + Hire machine cost, if any) × Days of downtime. On a machine that sells services, this item can easily exceed the difference in part price, especially when you add the days spent waiting for the part to arrive.
Questions to ask when buying aftermarket
If you are considering an aftermarket part, ask the seller these questions. Every point you can’t get a clear answer to means the risk stays with you.
- Who is the part’s manufacturer; are the brand and product code written on the part or the box?
- Which genuine part number does it replace; can the seller give this cross-reference in writing?
- Are the dimensions, material and pressure class the same as the genuine part; is there a technical data sheet?
- For filters, are the filtration fineness and bypass valve specified?
- For bolts, is there a property class marking?
- If the part doesn’t fit or fails quickly, what are the return and warranty terms?
- With the next order, will the same part come from the same manufacturer?
- Will the invoice state clearly whether the part is genuine or aftermarket?
We have gathered the model, serial number and part code information needed to identify a part correctly in our guide to finding the right spare part.
Signs that give away a counterfeit part
- A faded, missing or crookedly printed part number and logo
- Packaging with spelling mistakes and poor print quality
- Being noticeably lighter than a known example of the same part
- Rough casting, burrs and uneven machining marks
- A price far below the market and a seller who avoids identifying the part on the invoice
If you fit an aftermarket part, check it more often
If you decide to use an aftermarket part, watch it more closely in the first few weeks. Write the part’s brand, the date it was fitted and the operating hours in the maintenance log; at the next check, look at the condition of the filter element, for seepage at a seal or for loosening of a bolt. That way you decide whether to buy the same part again based on the result on your own machine, not on guesswork.
Choosing parts during the warranty period
If your machine is within the warranty period, choosing parts isn’t only a question of cost. How the parts and fluids used will be reflected in the warranty assessment is set out in the warranty certificate supplied with the machine, and that document is binding.
General good practice is: have periodic services done on time with oil and filters of the specification given in the manual, keep the invoices for the parts you use, and ask us before fitting a part you’re unsure about. The machines we sell at EKSFORK come with a 2-year or 2,000-operating-hour warranty; we explain what to watch to keep the warranty valid in our warranty guide.
Summary
- Make the decision not by price but by what happens if the part fails.
- For safety-critical parts and parts that cause knock-on damage, use genuine parts or parts with documented technical values.
- For wear and bodywork parts, aftermarket is a reasonable saving if the dimension and material information is clear.
- Calculate the real cost including replacement frequency, labour and downtime.
- Aftermarket is legitimate, counterfeit is not: ask for the invoice to state in writing what the part is.
You can browse parts that suit your machine’s model, category by category, on our spare parts page. Send the part name, machine model and part number, if you have it, on WhatsApp, and we will share the current price and delivery information.
