Catalog

SITRAK 812W251016021 HEADLAMP ASSY TRUCK

SITRAK 812W251016021 HEADLAMP ASSY TRUCK

Product Specifications

Product quality
OEM Equivalent Grade
starstarstar
Wholesale price USD $74.18
Wholesale price CNY ¥504
bolt MOQ (Minimal order)
50 pcs
local_shipping Production time
30-45 days
package_2 Shipping Weight: —
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SITRAK 812W251016021
Overview & Operating Principle
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The HEADLAMP ASSY TRUCK is a complete headlamp assembly for commercial trucks, heavy goods vehicles, and medium-duty transport platforms that integrates the full forward lighting system — low beam, high beam, position light, and on many designs the direction indicator — into a single sealed housing mounted in the cab front panel or fender aperture. Commercial truck headlamp assemblies are engineered to significantly higher structural and environmental standards than passenger car units: the housing is typically injection-moulded from UV-stabilised polycarbonate or glass-filled nylon capable of withstanding the vibration loads transmitted from the chassis through the cab mounting at laden gross vehicle weight on unpaved roads; the reflector is vacuum-metallised steel or thermoset polymer dimensionally stable at continuous operating temperatures up to 130°C from high-wattage halogen or HID sources; and all internal electrical connections use sealed waterproof terminals rated to IP67 to resist the water ingress from pressure washing that passenger car assemblies are not designed to withstand. The assembly mounts to the cab using three to five adjustment bolts or a quick-release bracket system that allows headlamp removal without tools in some fleet maintenance configurations, accommodating the frequent headlamp servicing schedule imposed by commercial vehicle regulatory inspections in most jurisdictions. The beam pattern complies with ECE R112 or ADR 13 for European and Australian markets respectively, with dedicated low-beam reflector and lens optics producing the asymmetric cut-off line that protects oncoming traffic from glare while maximising road illumination for the driver of the high-mounted commercial cab.

This unit — SITRAK 812W251016021 — is manufactured to OEM-equivalent specifications: housing outer profile and mounting bolt pattern for correct cab aperture fitment, reflector geometry for ECE-compliant beam pattern, bulb holder type and index position (H7, H4, H1, or HB3/HB4 depending on application), indicator lens colour and bulb holder for the integrated turn signal, wiring connector pinout, adjustment screw positions and range, and overall assembly weight for cab mounting bracket load rating are matched to the original part. Supplied as a complete assembly ready for installation. Available wholesale from 74.18 USD, MOQ 50 pcs, production lead time 30-45 days.

Commercial truck headlamp assemblies fail through lens hazing and yellowing from the intense UV exposure and road chemical environment at the front of a working vehicle — a hazed lens scatters the beam and reduces road illumination to a fraction of the assembly's design output, creating a safety and regulatory compliance issue; through housing cracking from stone impacts and chassis vibration fatigue at the mounting point stress concentrations; and through reflector coating degradation from moisture ingress through a cracked lens or failed housing seal that forms behind the lens and permanently etches the metallised surface. Unlike passenger car headlamps where hazing is a cosmetic issue, a hazed commercial vehicle headlamp on a vehicle operating at night on rural roads is a significant safety deficiency that must be addressed promptly to maintain roadworthiness certification.

Symptoms & Diagnostics
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Severely reduced road illumination compared to a new assembly despite functional bulbs confirmed by substitution — the polycarbonate lens has hazed from UV degradation, reducing light transmission and scattering the beam; compare both headlamps at night against a flat surface — a hazed assembly produces a diffuse glow rather than a sharp low-beam cut-off line; on commercial vehicles this condition will fail a roadworthiness inspection and must be addressed immediately.
Condensation or water pooling inside the housing visible through the lens — the housing seal or the lens-to-housing bond has failed; sustained moisture inside the assembly corrodes the reflector coating within weeks of ingress, producing a permanently degraded beam output that cannot be restored by drying the assembly; replace the complete assembly when moisture contamination of the reflector is confirmed.
Cracked or shattered lens from stone impact or collision damage — a cracked lens is an immediate roadworthiness defect on commercial vehicles subject to periodic technical inspection; water ingress through the crack will corrode the reflector within days of the crack forming; replace the assembly before the vehicle's next scheduled journey if immediate replacement is not possible, covering the crack with temporary waterproof tape to limit reflector damage.
Headlamp aim that has shifted from its adjusted position and cannot be restored by the aim adjustment screws — the mounting bracket or housing mounting tabs have cracked from chassis vibration fatigue, allowing the assembly to move within its mounting aperture; a headlamp that cannot be aimed correctly to the regulatory specification will fail a commercial vehicle inspection regardless of beam quality.
Integrated direction indicator inoperative with bulb and fuse confirmed serviceable — the indicator bulb holder or wiring connector within the assembly housing has corroded or fractured; on assemblies where the indicator circuit is integral to the housing and cannot be separately serviced, replace the complete assembly to restore indicator function required for road legal operation.
Housing body cracked at a mounting point or at a corner radius from impact or vibration fatigue — a cracked housing that has not yet affected the lens will allow moisture ingress to the reflector at the crack; on a commercial vehicle subject to continuous vibration loads, a crack in the housing body will propagate rapidly; replace before the crack reaches the lens mounting track and allows complete lens separation.
Logistics & Customs
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International HS Code
8512.20
EAEU Customs Code (TN VED)
8512 20 900 0
Typical Net Weight
Country of Manufacture
China
Standard MOQ
50 pcs
Production Lead Time
30-45 days
Always verify the exact 8-digit or 10-digit subheading with your customs broker for the destination country, as tariff schedules and duty rates vary by jurisdiction.
Installation Tips
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  1. Confirm the replacement assembly is the correct side and market specification before installation — commercial truck headlamp assemblies for left-hand-traffic (European, Asian) and right-hand-traffic (UK, Australian) markets have different low-beam cut-off angles built into the reflector geometry; the market specification is marked on the lens or housing; fitting the wrong-market assembly produces glare for oncoming drivers on the affected side and will fail a roadworthiness beam aim test regardless of correct aim adjustment.
  2. Transfer all bulbs from the old assembly to the new one before installation — on assemblies where the bulbs are separately accessible, always transfer the existing bulbs if they are within their service life; where the bulbs are at end of life or if any are damaged, replace all bulbs in the assembly with new units of the correct specification simultaneously — mismatched bulb ages produce unequal colour temperature and output between the two headlamps that is noticeable to the driver and to oncoming traffic.
  3. Inspect the cab mounting aperture for deformation, corrosion, and mounting tab integrity before fitting the new assembly — a mounting aperture that has been distorted by a previous impact will not allow the new assembly to seat correctly against its sealing face; a corroded mounting surface will prevent the adjustment bolts from torquing to the designed clamping load; clean and treat the aperture surface before fitting the new assembly to ensure correct sealing and structural support.
  4. Route and secure the wiring harness connector away from hot engine bay surfaces and moving components before connecting — commercial truck headlamp harnesses are longer than passenger car units and have additional slack for cab tilt access; secure the harness with the original routing clips to prevent chafing against the cab hinge area or contact with the engine cooling system components visible when the cab is tilted for maintenance access.
  5. Set headlamp aim using a calibrated commercial vehicle headlamp aim screen or beam setter after installation — commercial trucks require precise beam aim to comply with ECE R48 and national roadworthiness standards; the elevated cab height means a small angular error in aim produces a significantly longer beam displacement at road surface level than the same error on a passenger car; always aim with the vehicle at its designed laden height and with the fuel tank at half capacity to represent the standard weighing condition.
  6. Install the new HEADLAMP ASSY TRUCK (SITRAK 812W251016021), connect all wiring connectors until they click, confirm all functions — low beam, high beam, position light, and direction indicator — operate correctly, adjust the beam aim to the regulatory specification on a calibrated aim screen, and verify both headlamps produce a matched sharp cut-off line at the correct height before returning the vehicle to service.
Tools: commercial vehicle headlamp aim screen or beam setter calibrated for the cab mounting height, torque wrench for mounting bolts, sealed waterproof connector grease for connector reassembly, new bulbs of correct specification where replacement is required.
Frequently Asked Questions
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Should both headlamp assemblies be replaced simultaneously when only one is damaged or failed?
Replacing only the damaged or failed assembly is the correct targeted repair when the opposite assembly is confirmed serviceable and its beam quality, lens clarity, and reflector condition are within acceptable limits. However, on commercial vehicles where both assemblies show significant lens hazing — typically after 5–8 years of operation in road salt and UV-intensive environments — replacing both simultaneously during a planned maintenance stop eliminates the visual mismatch between a new clear-lens assembly and a heavily hazed opposite unit, and ensures both assemblies comply with the beam photometric requirements of the next periodic technical inspection. ok.parts supplies truck headlamp assemblies individually and in left-right pairs at wholesale MOQ from 74.18 USD per unit.
What are the regulatory beam aim requirements for commercial truck headlamps and how are they verified?
Commercial truck headlamp aim requirements are defined by ECE R48 in European markets — the low-beam cut-off line must fall at a specified height at 25 metres, varying by headlamp mounting height above the road surface; the exact requirement is determined by the vehicle's h value (headlamp centre height) and is typically set at a downward inclination of 1.0–2.0% below horizontal. Verification requires a calibrated headlamp aim tester positioned at the correct distance with the vehicle on a level surface at the specified laden state. Many national roadworthiness inspection schemes require beam aim to be checked at every periodic technical inspection — incorrectly aimed headlamps that produce glare to oncoming traffic are a fail item that grounds the vehicle from operation until corrected.
How does the OEM-equivalent aftermarket unit compare to the genuine OEM part?
OEM-equivalent units in this catalogue replicate the current OEM design geometry and material specification. Quality is verified against OEM cross-reference data. When ordering in bulk, confirm with our team that the specification matches the latest OEM revision for your application.
Is white-label or custom packaging available for wholesale orders?
Yes. ok.parts works directly with the manufacturing facility and can accommodate neutral white-label packaging or fully branded packaging with your company logo, part numbers, and barcode. Minimum order quantities and lead times for custom packaging may differ from standard stock. Contact the team via the inquiry form to discuss your specific requirements.
Frequently Replaced Together
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PartReason for Combined Replacement
Headlamp Bulb Set
H7, H4, H1 — specification per application		Headlamp bulbs in commercial vehicles accumulate operating hours at a significantly higher rate than passenger car bulbs due to the longer daily operating periods of commercial transport — a truck operating 10–12 hours per day with frequent night driving consumes bulb service life at 3–4 times the rate of a private vehicle. Replacing all bulbs simultaneously with the new assembly ensures the new optical system operates at full photometric output from installation and eliminates early bulb failure within the new assembly's first months of service.
Side Marker and Clearance Lights
Application-specific — front position and marker lights		Commercial trucks must comply with ECE R7 and national lighting regulations requiring operational side marker and clearance lights at all times — any inoperative lighting item is a roadworthiness defect. When a headlamp assembly is replaced following collision damage or housing failure, inspect all adjacent marker lights for damage simultaneously; a vehicle stopped for headlamp replacement that is also found to have inoperative marker lights requires both faults to be corrected before the vehicle can return to service.
Headlamp Wiring Harness Connector
Application-specific waterproof connector assembly		The wiring harness connector at the headlamp is subject to pressure washing, road water ingress, and vibration-induced terminal fretting over commercial vehicle service life. A connector with corroded or loose terminals produces the same inoperative headlamp symptom as a failed assembly — and a corroded connector fitted to a new headlamp assembly will immediately begin degrading the new assembly's electrical performance. Inspect and replace the connector when fitting a new headlamp assembly to ensure the new unit receives clean, full-voltage supply to all circuits.