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The 1K0412303E strut bump stop is the front axle suspension buffer that Volkswagen Group catalogs list under the description rubber stop for shock absorber, 55MM version. It slides over the piston rod of the front damper, sits inside the dust cover tube, and cushions the final stage of suspension travel before metal parts can contact each other. Because the same 55 mm buffer serves a long list of VW, SEAT, Skoda and Audi platforms, the 1K0412303E is one of the most frequently requested bump stops among European auto parts importers. This guide summarizes fitment, dimensions, cross references and purchasing options for wholesale buyers.
A strut bump stop, sometimes called a jounce bumper or auxiliary spring, is a compression element made of dense micro-cellular polyurethane foam. Under normal driving the damper controls wheel movement and the buffer stays clear of the rod guide. When the suspension compresses fully, for example on a sharp pothole or with a heavy load, the bump stop becomes the last line of defense. It compresses at a progressive rate, absorbs the impact energy and prevents the damper casing, spring seat and chassis from striking each other.
On this application the catalog height is 55 mm, which places the 1K0412303E in the shorter height group of the 1K0412303 family. The part weighs only about 45 grams, yet a failed buffer can lead to damaged struts, broken spring seats and complaints about harsh ride quality. Replacing this low cost component during suspension work is a simple way for workshops to avoid those failures. You can compare this reference with other items in the polyurethane bump stop range.
The 1K0412303E covers front strut suspensions across several Volkswagen Group platforms. Dealer and aftermarket catalogs list it for the models below. Exact application always depends on the PR code of the individual vehicle, so confirm the chassis number before committing a large order.
| Model | Years | Notes |
|---|---|---|
| VW Golf V, VI, VII | 2003-2016 | German and Mexico builds, PR code dependent |
| VW Jetta A5, A6 | 2005-2018 | US sedan; dealer catalogs also list the 2024 Jetta GLI |
| VW CC and Passat CC | 2009-2016 | Front axle, 2 buffers per car |
| VW Eos | 2006-2016 | Including ride control versions |
| VW Beetle A5 | 2011-2016 | PR-G45 with 2UA or 2UC, 1 buffer per car |
| VW Golf SportWagen and Alltrack | 2015-2019 | MQB platform, US market |
| VW Arteon | 2017 onward | Listed in current dealer catalogs |
| SEAT Altea | 2004-2015 | Quoted in protection kit catalogs |
| SEAT Toledo | 2004-2009 | Quoted in protection kit catalogs |
| Skoda Octavia II | 2004-2013 | Quoted in protection kit catalogs |
Two points matter for procurement planning. First, the reference remains active in current dealer catalogs, which list it for newer US market models such as the Jetta GLI and Arteon, so demand is not limited to older cars. Second, protection kits that pair the buffer with a dust cover also quote this OE number, which increases the sellable configurations built on the same tooling.
VW fitment data ties this buffer to combinations of suspension PR codes. Codes with a G prefix describe the front damper setup, while 2UA and 2UC describe standard and firmer suspension variants. Catalog excerpts show, for example, PR-G45 with 2UA or 2UC for the Beetle A5, PR-G01, G02, G03, G05 and G58 combinations for Golf builds produced in Germany and Mexico, and PR-2UC with G47 or G56 for the Jetta. Dealer catalogs also separate ride control, comfort suspension and sport suspension versions of the same models.
Quantity per car varies with the application. The Beetle A5 and several Jetta builds list one buffer per vehicle, while the CC and Passat CC list two for the front axle. Importers should therefore stock this item both as single units and as pairs.
Bonpora manufactures the 1K0412303E equivalent under its own reference 4110020. Key dimensions follow the original catalog data.
| Parameter | Value |
|---|---|
| OE reference | 1K0412303E (1K0 412 303 E) |
| Bonpora part number | 4110020 |
| Material | Polyurethane, micro-cellular foam |
| Bore, inner diameter | 19.5 mm |
| Outer diameter | 60.8 mm |
| Height | 55.4 mm (catalog specification 55 mm) |
| Fitting position | Front axle, left or right |
| Warranty | 1 year |
| Delivery time | 15 to 30 days |
| Packaging | Neutral export packaging |
| Custom service | OEM and custom design support |
The official catalog height for this reference is 55 mm, while the shipped Bonpora part measures 55.4 mm. This small difference reflects normal production and measurement tolerance for micro-cellular polyurethane and does not affect installation or function.
Volkswagen revised the front buffer several times as suspension variants evolved. The suffix letter marks the revision, and each revision targets specific PR code combinations. Aftermarket cross reference tables show related numbers such as 1KD412303, 3C0412303A and 5QD412303 next to the 1K0412303E. Some of those entries describe taller buffers around 70 mm, so buyers should never substitute by base number alone. Verify the height, the bore diameter and the PR code before mixing references in one shipment.
The E and F versions share the same 55 mm height and front axle position. Several aftermarket brands treat them as interchangeable references, and Febi lists one replacement number that covers both letters while another Febi number is dedicated to the E version. In practice a buyer searching for F will often find E offered as the equivalent, and the reverse is also true. For fleet and wholesale orders, the safe procedure is to read the OE suffix printed on the removed part, check the vehicle PR code, and match the buffer height of 55 mm.
Because applications span more than a decade of production, mixed pallets of Golf, Jetta, CC and Beetle buffers move quickly for European distributors. Confirm suffix letters at the quotation stage, keep the 55 mm E and F references separated in your warehouse system, and label cartons with the full OE number to reduce returns and mis-shipments.
The table below lists established aftermarket equivalents that buyers and procurement teams use when sourcing this buffer.
| Brand | Part number | Format |
|---|---|---|
| Febi Bilstein | 23458 | Single buffer, front axle, 55 mm |
| Febi Bilstein | 1003740 | Kit with 2 buffers and 2 dust covers |
| Meyle | 100 642 0003 | Single buffer |
| SKF | VKDP 33109 T | Protection kit, 2 buffers and 2 bellows |
| KYB | 910057 | Protection kit, front axle |
| VAICO | V10-6029 | Single buffer, 55 mm |
| SASIC | 9005334 | Single buffer |
When searching supplier catalogs, try the OE number in several formats, including 1K0412303E, 1K0 412 303 E and 1K0 412 303E, because different databases index the reference differently. Brands such as Febi, SKF and KYB sell this reference as a protection kit that combines the buffer with the bellows, which is a useful upsell next to the single part.
Polyurethane foam ages with ozone exposure, heat and repeated compression. Inspect the buffer whenever the front struts are removed. Cracks, crumbling edges or a flattened profile mean the part has lost its progressive response and should be renewed.
A worn or missing buffer allows the suspension to reach full compression without protection. Drivers notice a hard clunk over potholes and speed bumps, and the damper rod guide or spring seat can suffer damage over time. If a vehicle shows these symptoms, check the buffer together with the dust covers, because a torn bellows lets grit attack both the piston rod and the buffer.
Workshops normally renew the bump stops and dust covers whenever struts are replaced, since the shared labor makes the combined job economical. On models that carry two front buffers, replacing both sides keeps the suspension response symmetric.
Bonpora produces suspension buffers in polyurethane with controlled density and hardness, and the company develops tooling for each family reference in-house. For the 1K0412303 program this covers the 55 mm front versions as well as related heights within the same base number series. Buyers who need their own branding, custom packaging or dimensional adjustments can use the custom parts service, which supports OEM projects from sample confirmation to volume production.
The 4110020 buffer ships in neutral export packaging suitable for resale under your own label. Standard delivery time is 15 to 30 days depending on order volume, and the part carries a 1 year warranty. Bonpora accepts small trial orders for market testing as well as repeated volume programs for distributors.
Request a quotation. Send the OE number 1K0412303E, your target quantity and destination port, and the sales team will confirm price, packing and lead time for your market.
Both references describe a 55 mm front axle buffer in the same family, and major aftermarket catalogs treat E and F as interchangeable. The E version covers specific PR code combinations and remains active in current dealer catalogs, while F covers other production ranges. Confirm the suffix on the removed part or the vehicle PR code before ordering.
It depends on the model. Catalog data shows quantity 1 per vehicle for the Beetle A5 and several Jetta builds, and quantity 2 for the front axle of the CC and Passat CC. Stock singles and pairs to serve both cases.
The catalog height is 55 mm. The Bonpora 4110020 equivalent measures 19.5 mm inner bore, 60.8 mm outer diameter and 55.4 mm height, which is within normal tolerance of the original specification.
Yes. Brands such as Febi, SKF and KYB sell this reference as a protection kit containing buffers and bellows for both sides. Bonpora supplies the buffer as a single part and can discuss custom kit configurations for distributor programs.
