Catalog

SUZUKI 41111A78B10 SPRING COIL

SUZUKI 41111A78B10 SPRING COIL

Product Specifications

Product quality
OEM Equivalent Grade
starstarstar
On request
bolt MOQ (Minimal order)
1 pcs
local_shipping Production time
45-50 days
package_2 Shipping Weight: —
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SUZUKI 41111A78B10
Overview & Operating Principle
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The SPRING COIL is the suspension coil spring — the primary elastic load-bearing element of the wheel suspension that supports the vehicle's sprung mass above each wheel, maintains the designed ride height under static load, and stores and releases elastic energy during suspension travel to allow the wheel to follow road irregularities while minimising the displacement transmitted to the vehicle body. The spring is a precision-formed helical steel coil wound from high-strength chromium-silicon or chromium-vanadium alloy steel wire that has been shot-peened to introduce beneficial compressive residual stresses in the surface layer, significantly increasing resistance to fatigue crack initiation; the spring rate — the force required to compress the spring by one unit of displacement, typically 15–35 N/mm on passenger cars — is determined by the wire diameter, coil diameter, number of active coils, and steel modulus, and is precisely calibrated for each vehicle corner to achieve the desired natural frequency of the sprung mass that determines ride quality. The spring works in conjunction with the shock absorber — which controls the velocity of spring compression and extension — and the bump stop — which provides a progressive end-stop at maximum compression — to form the complete wheel location and comfort system; the spring alone determines the vehicle's static ride height and the frequency of body bounce, while the damper controls how quickly the spring oscillation dies after a road disturbance.

This unit — SUZUKI 41111A78B10 — is manufactured to OEM-equivalent specifications: wire diameter, coil diameter, free length (unloaded height), spring rate in N/mm, number of active coils, end coil geometry for the spring seat interface, surface treatment — epoxy or plastisol coating — for corrosion resistance, and the installed (compressed) height at the vehicle's designed laden ride height are matched to the original part. Supplied individually as a direct replacement for standard fitment. Available wholesale from 0.18 USD, MOQ 1 pcs, production lead time 45-50 days.

Coil springs fail through two mechanisms: fatigue fracture and elastic fatigue (settling). Fatigue fracture — the sudden cracking and separation of a spring coil — occurs at the lower coil's contact zone with the spring seat where road salt accumulates between the coil and the seat surface, causing accelerated corrosion that pits the steel surface; this pit becomes a fatigue crack initiation site that propagates under the cyclic bending stress of normal suspension travel until the coil fractures suddenly. Elastic fatigue — gradual reduction in free length from loss of the steel's elastic limit after high-cycle accumulation — produces a vehicle that sits progressively lower at the affected corner, measurable as a ride height reduction of 10–30 mm over the spring's service life. Both failure modes affect springs identically on both sides of an axle, which is why springs are always replaced in axle pairs.

Symptoms & Diagnostics
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Vehicle sitting noticeably lower at one corner than the other three — the body is visibly tilted in one direction when viewed from the front or rear on a level surface — one spring has either fractured (sudden height loss) or settled below the opposite spring (gradual height loss); measure the ride height at all four corners — distance from the wheel arch lip to the wheel centre — and compare left to right on each axle; a difference greater than 10–15 mm between matched corners confirms spring failure or inequality.
Clunking or metallic scraping noise from one suspension corner over speed bumps or rough road surfaces — the noise is metallic and abrupt, unlike the rubbery thud of a failed bump stop — a fractured coil spring has produced a broken coil end that contacts the adjacent coil or the spring seat on every compression cycle; inspect the spring visually with the vehicle raised — a fractured spring has an obvious break with sharp steel edges visible between the coils.
Tyre contact with the inner wheel arch liner or suspension components at full bump — the tyre is rubbing on the arch when the wheel travels upward — severe spring settling has reduced the ride height to the point where the designed bump travel reserve is exhausted and the wheel reaches its clearance limit under normal suspension travel; the rubbing is typically accompanied by a rhythmic thumping from the tyre contact.
Wheel alignment that cannot be set within the OEM specification despite correct suspension geometry — camber or caster reads outside its adjustment range — spring settling has changed the suspension's static geometry by moving the spring seat and shock absorber attachment point relative to the designed position; the static alignment change is measurable and reproducible but cannot be corrected by the alignment adjusters alone without restoring the correct ride height.
Progressive worsening of ride quality — the vehicle feels harder over small road irregularities while retaining normal compliance over large impacts — spring elastic fatigue has reduced the free length without fracturing the coil; the shorter spring sits closer to the bump stop in normal driving, engaging the bump stop's high spring rate on small road inputs that previously did not reach the bump stop; this characteristic distinguishes settled springs from shock absorber failure which affects all amplitudes equally.
Visible corrosion pitting or rust at the lower coil contact zone — orange-brown surface corrosion concentrated at the point where the lower coil contacts the rubber spring pad on the spring seat — the protective coating has failed at this high-stress contact point where road salt accumulates; even without fracture, a spring with deep corrosion pitting at the lower coil has developed fatigue crack initiation sites that make imminent fracture under the next high-amplitude impact likely; replace preventively.
Logistics & Customs
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International HS Code
7320.20
EAEU Customs Code (TN VED)
7320 20 890 0
Typical Net Weight
Country of Manufacture
China
Standard MOQ
1 pcs
Production Lead Time
45-50 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. Use two independent coil spring compressors symmetrically positioned on opposite sides of the spring before removing the strut top mount nut on MacPherson strut designs — the coil spring stores significant elastic energy under its preload; releasing this energy suddenly by removing the top nut without compressors sends the spring, strut bearing, and top mount across the workshop with potentially fatal force; always confirm both compressors are fully engaged and under visible load before loosening the top nut by even one turn.
  2. Transfer the spring seat pad and the dust boot and bump stop assembly to the new spring before installation — the rubber spring seat pad that locates the spring's lower coil end on the spring seat must be fitted in the correct orientation to the new spring; the upper coil end must engage the upper spring seat's locating recess correctly; a spring installed with either end mislocated will rotate on its seat during suspension travel and produce a creaking noise from the first kilometre.
  3. Confirm the new spring's free length matches the old spring's specification before compression — hold the new and old springs side by side in their free (uncompressed) state and compare; a spring that is significantly shorter than the old spring is the wrong spring rate or has already settled before installation; a spring that is significantly longer may be a higher-rate spring from a different variant of the vehicle; the free length difference should be within 5 mm of the original.
  4. Replace springs in axle pairs simultaneously without exception — fitting one new spring and retaining the opposite corner's settled spring produces a permanent ride height difference between left and right that cannot be corrected by alignment adjustment; the vehicle will lean permanently to the higher (new spring) side under static load and handle asymmetrically in cornering; the axle-pair replacement rule applies even when only one spring has fractured, because the opposite spring has accumulated the same corrosion and fatigue cycles and is at imminent risk of fracture.
  5. After installing both springs, measure the ride height at all four corners before performing a wheel alignment — place the vehicle on a level surface at its normal unladen weight and measure the distance from the wheel arch lip to the wheel centre on all four corners; all measurements should be within the OEM specification range and within 10 mm of each other on the same axle; only proceed to alignment when the ride height is confirmed correct — alignment performed at incorrect ride height will need to be repeated after ride height settles.
  6. Install the new SPRING COIL (SUZUKI 41111A78B10) on both corners of the axle simultaneously, perform a four-wheel alignment after confirming correct ride height on all four corners, road test over a range of road surfaces confirming correct ride quality and no metallic noise from either spring corner, and recheck ride height after 500 km as new springs may settle fractionally during initial service before returning the vehicle to service.
Tools: two independent coil spring compressors per strut (minimum), ride height measuring tape or dedicated ride height gauge, torque wrench for top mount nut, four-wheel alignment equipment after installation.
Frequently Asked Questions
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Why must both springs on the same axle always be replaced simultaneously, even when only one has failed?
Both springs on the same axle accumulate identical corrosion damage, fatigue cycles, and elastic fatigue from exposure to the same road environment over the same mileage — if one spring has fractured or settled, the other is at the same failure stage. Installing one new spring of the original design free length against an opposite spring that has settled 15–20 mm permanently raises one corner of the axle above the other, producing a static cross-axle ride height difference that makes the vehicle lean, handle asymmetrically in cornering, and wear its tyres unevenly. Additionally, a new spring against a settled opposite spring places different loads on the left and right shock absorbers, accelerating the wear of the overloaded unit. The incremental cost of a second spring is small relative to the repeat alignment, tyre wear, and shock absorber replacement costs that result from single-spring installation. ok.parts supplies springs individually and in axle pairs at wholesale MOQ from 0.18 USD per unit.
Does spring replacement require wheel alignment afterwards, and which angles are affected?
Wheel alignment is mandatory after coil spring replacement on any axle. The coil spring's free length determines the suspension's static geometry — the position of the wheel relative to the body at ride height — which directly affects camber, caster on independent rear suspension designs, and toe on suspension designs where the spring seat position influences the control arm geometry. A new spring of the same rate will restore the designed ride height, returning the geometry toward the OEM specification, but the exact position will differ from both the settled spring's geometry and the theoretical OEM geometry due to spring manufacturing tolerances and accumulated wear in adjacent joints. Full four-wheel alignment must be performed and all adjustable angles confirmed within OEM specification after spring replacement on any axle.
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
Shock Absorber
OEM ref. varies by axle position		The shock absorber and coil spring are accessed simultaneously through spring compression and strut disassembly, and accumulate the same mileage and operating cycles. A shock absorber that has been operating alongside a settled or fractured spring has been working at incorrect static extension lengths, accelerating wear of its piston rod seal and valve stack. Assess the shock absorber's damping performance while the spring is compressed — a damper that bounces more than one and a half times when the vehicle corner is pressed and released has insufficient damping and should be replaced simultaneously with the spring.
Strut Top Mount and Bearing
OEM ref. varies — MacPherson strut applications		The strut top mount bearing is fully accessible and under zero load when the spring compressors are in place — this is the only time the bearing can be inspected and replaced without additional labour. The top mount bearing accumulates the same mileage as the spring and is subject to the same thermal and moisture cycling; a bearing that produces roughness when rotated by hand while the spring is compressed should be replaced simultaneously with the spring to avoid a repeat spring compression operation within a short interval.
Spring Seat Pad (Rubber Isolator)
Upper and lower rubber seats		The rubber spring seat pads that locate the spring's upper and lower coil ends against the strut and spring seat metal faces provide acoustic isolation between the spring steel and the body structure and protect the spring's coating from abrasion at the contact points. Pads that have hardened, flattened, or torn allow metal-to-metal contact between the coil and the seat that produces a spring creak or click on every suspension compression cycle. Always replace the spring seat pads simultaneously with the springs — the pad cost is negligible and a creaking spring contact produces the same complaint as a failed bearing that requires repeat disassembly to diagnose.