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A strut bump stop is the last line of defence inside a front suspension strut. It sits on the piston rod, hidden by the dust boot, and takes the final stage of compression so that the damper rod never hits the top mount metal to metal. This page presents the Strut Bump Stop with OE reference 5Q0511357G and Bonpora No. 4110055, a polyurethane buffer made in China for Volkswagen, Audi, Seat, and Skoda applications. The sections below cover function, specification, OEM cross-reference, wholesale supply, custom manufacturing, and installation notes for importers, distributors, and workshops.
During normal driving the coil spring carries the weight of the vehicle and the damper controls body motion. When a wheel drops into a deep pothole or rides over a sharp edge, the remaining travel is consumed in a fraction of a second. At that moment the bump stop is compressed between the spring seat area and the top mount region of the strut. Because polyurethane compresses progressively, the part works like a secondary spring: soft on first contact, then firm as compression deepens. That controlled curve protects the damper rod, the top mount bearing, and the surrounding body structure from a hard bottom-out.
When the stop is missing, cracked, or permanently squashed, the strut bottoms out directly. Drivers usually report a heavy knock over speed bumps, a bouncy or unsettled ride, and extra noise from the top mount area. Modern platform vehicles built by the Volkswagen Group use compact struts with limited travel, so the buffer carries a high share of the load and wears steadily with mileage. For a workshop the bump stop is one of the lowest-cost items to renew while the strut is already opened, and for a distributor it is a fast-moving wear part with repeat demand across four brands at once.
The OE prefix 5Q0 belongs to the parts numbering system used across the Volkswagen Group platform families, so this reference appears in catalogues for compact and mid-size models of all four brands, including Golf, Passat, Octavia, Superb, Leon, and A3 lines depending on market and model year. The stop slides over the piston rod of the front strut and sits under the dust boot, above the damper seal area. Exact fitment depends on model year, trim, and axle, so confirm the strut design of the specific vehicle before ordering. When in doubt, compare the bore, outer diameter, and free length with the removed original part.
| Parameter | Value |
|---|---|
| Product Name | Strut Bump Stop |
| Country of Origin | China |
| Bonpora Nos | 4110055 |
| OE | 5Q0511357G |
| Fitment | Audi / Seat / Skoda / Volkswagen |
| Size | Φ14.8 x Φ61.4 x 123 mm |
| Material | Polyurethane |
| Warranty | 1 Year |
| Delivery Time | 15-30 Days |
| Packaging | Neutral Export Packaging |
| Custom Service | OEM & Custom Design Support |
The size note Φ14.8 x Φ61.4 x 123 mm describes a slender stepped body: a 14.8 mm inner bore that fits over the piston rod, a 61.4 mm maximum outer diameter, and a 123 mm free length at rest. All three figures matter. The bore must seat on the rod shoulder, the outer diameter must clear the dust boot without rubbing, and the free length sets the point at which the stop starts to work. A stop that is even slightly too long will preload the suspension and change ride height, while one that is too short lets the strut bottom out early. Buyers should check the dimensions against the original part or vehicle data before confirming an order.
Polyurethane is chosen ahead of ordinary rubber for its resistance to oil, ozone, road salt, and repeated compression. It keeps its shape longer under load, which is valuable on vehicles that often run fully loaded or on rough roads, and it is the standard material class for this OE reference family. The longer working life also suits markets with hot climates, where rubber buffers tend to harden and crumble early.
Sourcing by OEM number is the fastest route when the original part is still readable. The number 5Q0511357G identifies this bump stop in Volkswagen Group parts listings, and the G suffix marks a revised version of the base 5Q0511357 reference, a pattern that is common when the vehicle maker updates a component during the production cycle. The number points to one Bonpora No. 4110055, so distributors and repeat buyers can reorder a single specification without re-checking drawings. The wider auto parts catalogue groups these references by system and by vehicle model, which shortens quotation work for mixed orders.
If the OE number has worn away, identify the part by vehicle instead: brand, model, model year, engine, and front or rear axle. Supplying the VIN removes ambiguity between trim levels that use different strut hardware. Workshops that handle several VW Group brands in one bay can order one Bonpora number and cover all four marques, which simplifies stock keeping.
This bump stop is produced in China for wholesale distribution. The factory runs the part as a catalogue item, which means tooling already exists, dimensions stay stable between batches, and pricing is structured for container and pallet quantities rather than single-piece retail. Typical buyers are importers of suspension and rubber parts, national and regional parts distributors, fleet maintenance operators, and online sellers who need a dependable source for VW Group fast movers. The suspension and rubber parts range from the same production site covers companion items usually ordered together.
Orders are packed in neutral export packaging by default, so the goods arrive ready for relabelling under the own brand of the distributor. Delivery time is 15 to 30 days depending on order volume and production scheduling, and the warranty period is 1 year. For first-time customers, sample quantities can be arranged before a bulk commitment so that fitment can be verified on real vehicles.
Each production batch is checked for bore diameter, outer diameter, free length, and material hardness. Visual inspection covers flash, voids, and surface defects that could lead to early cracking. Dimensional records are kept per batch, so repeat orders match the approved sample rather than drifting over time.
Beyond the catalogue part, the same production line supports OEM and custom design work. Options include tailored polyurethane hardness, adjusted free length, bore, or outer diameter, coloured material for brand recognition, branded packaging, and private-label marking. Distributors serving a defined vehicle parc often combine several suspension items in one shipment to reduce freight cost per unit. For a custom project, send a drawing or a physical sample together with the expected annual volume. Tooling and sampling lead times are quoted separately from mass production, and a first-article sample is normally supplied for fitment confirmation before the production run starts.
Replace bump stops in pairs on the same axle, and inspect the dust boot, top mount bearing, and spring seat at the same time. A collapsed stop usually means the strut has been bottoming out, so check the damper for oil loss before refitting. Torque the top mount nut to the figure given by the vehicle maker, with the suspension at normal ride height where the design calls for it.
A polyurethane stop should seat fully on the piston rod shoulder. If it does not sit flat it will wear unevenly and may generate noise within a short mileage. Because the buffer is compressed inside the boot, a light coating of the grease specified by the vehicle maker makes future removal easier and reduces the risk of squeaking.
Typical signs are a hard knock over speed bumps, a bouncy or unsettled ride, and visible cracking, crumbling, or permanent compression of the old stop. If the strut has been bottoming out, inspect the damper for oil seepage at the same time, because a failed buffer often shortens damper life.
The reference belongs to the 5Q0 numbering family used across Volkswagen Group platforms, and it is listed for compact and mid-size models of Volkswagen, Audi, Seat, and Skoda depending on market and model year. Confirm the model year and axle against the parts catalogue, or send the VIN for a precise match.
Yes. OEM and custom design support is available, including adjusted polyurethane hardness, modified free length, bore, or outer diameter, and private-label packaging. Send a drawing or sample with the target annual volume for a quotation.
Delivery time is typically 15 to 30 days depending on quantity. Packaging is neutral export packaging by default, with branded options available on request, and the warranty period is 1 year. Sample quantities and mixed-container loading with other suspension parts can be arranged for new customers.
Send us the OEM number 5Q0511357G, the Bonpora number 4110055, the quantity, and the destination port. We will confirm specification, packing, and delivery schedule. For buyers comparing several sources, the full auto parts line covers suspension, steering, and engine components from the same factory.
