FIAT/ALFA/LANCIA 51814082 DOOR ROLLER
Product Specifications
Product quality
OEM Equivalent Grade
25 sold
Wholesale price USD
$7.02
Wholesale price CNY
¥48
bolt MOQ (Minimal order)
25 pcs
local_shipping Production time
27 days
package_2 Shipping Weight:
0.95 kg
swap_horiz
Application (cross references) 1
expand_more
| FIAT/ALFA/LANCIA | 51814082 |
Overview & Operating Principle
▲
The DOOR ROLLER is a sliding door guide roller assembly — a flanged steel or nylon-wheeled roller unit that runs within the sliding door's guide rail track system, carrying the door's weight and guiding its lateral movement along the designed arc from the fully closed latched position to the fully open position on vans, MPVs, and minibuses. Modern sliding door systems use three roller assemblies per door — an upper roller that runs in the upper guide rail above the door aperture, a lower roller that runs in the lower rail at the door sill level, and a centre rear roller that runs in the main centre rail along the vehicle's side body — with each roller assembly contributing a specific load-bearing and guiding function in the door's movement: the centre rail roller carries the majority of the door's static weight and provides the primary fore-aft guidance; the upper roller controls the door's inward-outward position at the top and prevents the door from swinging out during opening; the lower roller maintains the door's position at the sill and prevents the door from dropping at its outboard edge. Each roller assembly consists of a hardened steel axle stud that bolts to the door inner structure, carrying a sealed ball bearing or plain bearing wheel — the roller proper — that runs against the guide rail's channel walls; on power sliding door systems the roller assembly may additionally carry the drive cable attachment point or the door position sensor magnet. The roller's flanges on both sides of the running surface keep the roller engaged within the rail channel without lateral displacement throughout the full door travel arc.
This unit — FIAT/ALFA/LANCIA 51814082 — is manufactured to OEM-equivalent specifications: roller outer diameter and wheel width for the rail channel geometry, axle stud thread and boss diameter for door inner panel attachment, bearing type and load rating for the door's static and dynamic weight, flange dimensions for rail engagement retention, and overall roller assembly geometry for upper, lower, or centre rail position as applicable are matched to the original part. Supplied as a complete roller assembly ready for installation. Available wholesale from 7.02 USD, MOQ 25 pcs, production lead time 27 days.
Sliding door roller assemblies fail through bearing wear from water ingress and lack of lubrication — the roller runs in an exposed rail that collects road spray, car wash water, and atmospheric moisture; a bearing that has lost its grease from water washout corrodes and seizes, causing the roller to drag rather than roll freely and producing a grinding or scraping resistance during door operation; through roller wheel fracture from an overload impact — a door that is opened rapidly and reaches its end stop with excessive force, or a door that is forced open against an obstruction, can fracture the nylon roller or damage the bearing; and through axle stud corrosion fracture at the door panel attachment point from sustained moisture exposure.
Symptoms & Diagnostics
▲
Sliding door that requires significantly more force to open or close than previously — the door drags during operation and does not slide smoothly through its full travel range — one or more rollers have seized or are binding in the rail from bearing failure or rail contamination; confirm which roller is binding by manually pushing the door open slowly while feeling for the specific travel position where the resistance increases — the binding location in the travel arc corresponds to the position of the failed roller relative to the rail entry point.
Grinding, scraping, or rumbling noise during door opening or closing — the noise occurs throughout the door travel or at a specific position in the travel arc — a seized roller is sliding rather than rolling along the rail contact surface, producing abrasive metal-on-metal or wheel-on-rail contact noise; or a roller with a fractured wheel is producing an impact noise once per revolution as the damaged section of the wheel contacts the rail; determine which roller by isolating the noise source with the door partially open and stationary.
Sliding door that sags at its outboard trailing edge — the rear lower corner of the door droops below the door aperture's lower edge when the door is open — the lower rail roller has failed or the centre rail roller axle has fractured, allowing the door's weight to be carried unevenly with the lower rear corner unsupported; inspect both the lower sill rail roller and the centre main rail roller for bearing condition and axle integrity.
Power sliding door that triggers its obstruction detection system and reverses during normal operation without any obstruction present — on electrically operated sliding doors — a seized roller is imposing a resistance force on the door drive motor that exceeds the obstruction detection threshold; the motor interprets the increased current draw from the dragging roller as an obstruction and reverses; confirm by manually pushing the door in the same direction — if the door moves with difficulty, the roller is the fault rather than the obstruction detection system.
Sliding door that rattles over rough road surfaces when closed — a metallic clicking or knocking from the door area that is speed-dependent and reproduced by pressing on the door panel — a worn roller bearing has developed radial play that allows the roller to knock within the rail channel on every road vibration; the rattle is often most audible from the rear passenger position adjacent to the affected door and can be confused with interior trim rattles until the source is isolated by door pressure testing.
Visible corrosion, deformation, or fracture of the roller assembly — worn-through roller flange, cracked nylon wheel body, or fractured axle stud visible on inspection with the door open and the roller accessible — direct visual confirmation of roller failure; any visible structural damage to a roller assembly requires replacement regardless of whether a symptom is currently detectable — a partially failed roller will progress to complete failure and potential door dropping under normal use.
Logistics & Customs
▲
International HS Code
8708.99
EAEU Customs Code (TN VED)
8708 99 970 9
Typical Net Weight
0.95 kg
Country of Manufacture
China
Standard MOQ
25 pcs
Production Lead Time
27 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
▲
- Support the sliding door on a floor jack or roller stand before removing any roller assembly — the sliding door on a van or MPV is a heavy panel, typically 30–60 kg; removing a roller assembly without supporting the door allows the door to shift its weight distribution suddenly, potentially pulling the remaining rollers out of their rails or dropping the door onto the operator; position a jack or stand under the door's outboard edge before loosening any roller mounting bolt.
- Identify the exact roller position — upper, lower, or centre rail — before ordering the replacement — the three roller assemblies on a sliding door are not interchangeable between positions; each has specific flange geometry, axle stud length, and bracket design matched to its rail position and load direction; confirm from the vehicle's parts catalogue which position the failed roller occupies before ordering to ensure the correct unit is supplied.
- Clean the guide rail channel thoroughly with degreaser and a long-handled brush before installing the new roller — accumulated road grit, dried grease, and corrosion deposits in the rail channel will immediately contaminate the new roller's bearing and wheel surface; a contaminated rail abrades the new roller's nylon wheel or bearing races from the first operation cycle; flush the full length of each affected rail with degreaser, agitate with a brush, wipe with a lint-free cloth, and dry with compressed air before lubricating and installing the new roller.
- Apply the OEM-specified rail lubricant — typically a lithium complex grease or a silicone-based aerosol — to the cleaned rail channel before roller installation — the rail requires lubrication at the roller contact zones to minimise rolling resistance and protect the bearing from moisture; do not use petroleum-based oil that will wash out with the first rain or engine degreasing, and do not use copper or molybdenum grease that is too thick for the rail channel clearance; apply the correct lubricant to the full rail contact length with a brush or aerosol before inserting the new roller.
- Torque the roller axle stud mounting bolt to the OEM specification — typical values are 15–35 Nm depending on the stud size and door weight; undertightening allows the roller bracket to shift angularly on the door panel, misaligning the roller in the rail channel and causing the flange to bind against the rail wall; overtightening distorts the door inner panel and may fracture the bracket's mounting boss on steel or aluminium door constructions.
- Install the new DOOR ROLLER (FIAT/ALFA/LANCIA 51814082), guide the door into its rails, operate the door through its full travel range confirming smooth movement with no binding, dragging, or noise at any position, confirm the door latches cleanly at the fully closed position with correct gap and flush alignment to the body, and on power doors confirm the obstruction detection system no longer triggers during normal operation before returning the vehicle to service.
Tools: floor jack or roller stand for door support, torque wrench (15–35 Nm), long-handled brush for rail cleaning, degreaser, compressed air for rail drying, lithium grease or silicone aerosol for rail lubrication.
Frequently Asked Questions
▲
Should all three sliding door rollers be replaced simultaneously when only one has failed?
Replacing all three rollers simultaneously is recommended when the vehicle has accumulated significant mileage and the failure is from bearing wear or corrosion rather than a specific impact event. All three rollers operate in the same environment with the same road spray and moisture exposure over the same mileage; if the centre rail roller bearing has failed from water ingress and grease washout, the upper and lower rollers are at the same stage of bearing degradation and will require replacement within a short interval. The labour to access and replace a sliding door roller is similar for all three positions — replacing all three in a single operation avoids two repeat services within a short period. When only one roller has failed from an impact or physical damage, replacing only the damaged unit is appropriate provided the remaining rollers spin freely and silently by hand. ok.parts supplies sliding door rollers individually and as complete three-roller sets at wholesale MOQ from 7.02 USD per unit.
How frequently should sliding door rollers and rails be lubricated as preventive maintenance?
Sliding door rails and rollers should be lubricated every 12 months or 20,000 km as part of a regular body lubrication service — this interval is reduced to every 6 months on vehicles that operate in high-humidity environments, coastal salt air, or winter road salt conditions where the lubrication washout rate is significantly higher. The lubrication procedure takes under 10 minutes per door: clean the exposed rail section with degreaser, dry, and apply lithium grease or a dedicated sliding door lubricant spray to the full rail length. Vehicles whose rails are lubricated at this interval consistently achieve roller bearing service lives two to three times longer than unlubricated examples of the same model — the maintenance cost is negligible compared to the labour for roller replacement on a commercial vehicle that operates multiple door cycles per day.
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
▲
| Part | Reason for Combined Replacement |
|---|---|
| Sliding Door Guide Rail Centre, upper, or lower — OEM ref. varies | A roller that has been seized and dragging rather than rolling along the rail has been grinding a wear groove into the rail's running surface at the contact point; a rail with a wear groove cannot provide a smooth running surface for the new roller and will produce noise and irregular resistance from the first operation cycle. Inspect the rail running surface for visible wear grooves, corrosion pitting, or deformation at the position where the failed roller was seated; replace the rail simultaneously if surface damage is found — a new roller on a damaged rail reproduces the original symptom within a short mileage. |
| Sliding Door Latch and Striker OEM ref. varies by door position | A sliding door with worn or failed rollers has been operating with incorrect lateral alignment throughout its travel — the misaligned door engages its latch against the striker at a shifted angle, causing accelerated wear of the latch fork and striker pin contact surfaces and potentially bending the striker mounting bracket. With the new rollers restoring correct door geometry, inspect the latch fork for wear and the striker for deformation; a latch that was worn by misaligned door operation may now engage incorrectly with a new, correctly positioned door and require replacement to restore clean latching. |
| Door Weatherstrip Seal Full perimeter seal — OEM ref. varies | A sliding door that has been dragging from failed rollers has been imposing abnormal loads on the weatherstrip seal at the door aperture perimeter on every open and close cycle — the misaligned door compresses the seal unevenly, causing permanent deformation and tearing at the points of greatest misalignment. With the door geometry restored by new rollers, inspect the weatherstrip for torn or permanently deformed sections that would admit water or wind noise despite the correct door alignment; replace the weatherstrip if any permanent deformation is found. |