sales@bonporaparts.com
0086-10-64988621
English
The strut bump stop 1643230044 is the front axle rubber buffer that Mercedes-Benz fits to the ML-Class W164 and the GL-Class X164 when the vehicle leaves the factory with steel spring suspension rather than AIRMATIC air suspension. Mounted on the piston rod of the front shock absorber, this progressive cushion takes the final phase of suspension compression and protects the damper, the top mount, and the body structure from hard metal to metal contact. This page presents Bonpora No. 4110192, a polyurethane replacement produced in China for wholesale distribution, matching the Mercedes-Benz reference A 164 323 00 44, also written 164-323-00-44 or 164.323.00.44. The sections below explain how the part works, confirm which ML and GL variants use it, list the dimensions and material, show how to source by OEM number, describe wholesale supply and custom manufacturing from a Chinese auto parts factory, and close with fitting notes and answers to the questions buyers ask most often.
The W164 ML and the related X164 GL use an independent front suspension with a coil spring and a gas filled shock absorber on each corner. In normal driving the spring carries the vehicle mass while the damper controls how quickly the body moves over the road. When a front wheel drops into a pothole, rides over a sharp ridge, or carries the weight of heavy braking into a deep compression, the full travel of the suspension is used up within a fraction of a second. At that point the bump stop, which sits on the damper rod behind the protection boot, is compressed between the rod and the top of the shock absorber housing. Polyurethane compresses along a progressive curve, so the part works as a secondary spring: soft on first contact, then progressively firmer as the remaining travel runs out. That staged ramp absorbs the last phase of the impact and keeps the piston, the rod guide, and the top mount from receiving the full force of a bottom out.
These are heavy vehicles. A laden ML 320 CDI towing a trailer, or a seven seat GL carrying passengers and luggage over broken road surfaces, drives the front suspension deep into its travel far more often than a saloon car. Once the buffer cracks, crumbles, or takes a permanent set, every hard compression reaches the damper unaided. Drivers notice a sharp knock from the front over expansion joints, a sudden harshness when the car is loaded, and body movement that no longer settles cleanly after a bump. Because the buffer hides behind the dust boot, worn units are often only discovered when the shock absorber is removed for another job. Workshops that service W164 and X164 vehicles therefore treat the bump stop as a standard renewal item together with the protection boot, the spring seat, and the top mount whenever front dampers are replaced.
The reference 164 323 00 44 is the stop for vehicles without AIRMATIC, in other words with conventional steel spring suspension. ML and GL models ordered with the AIRMATIC air suspension option use a different buffer profile designed around the air spring module, so the two parts are not interchangeable. Catalogue listings for this number cover the ML W164 from 2005 to 2011, including the ML 280 CDI, ML 300, ML 320 CDI and ML 320 Bluetec, ML 350, ML 420 CDI, ML 450 CDI and ML 450 Hybrid, ML 500, ML 550, and ML 63 AMG, and the same front stop is listed for steel spring applications on the GL X164 such as the GL 320 CDI and GL 350 CDI. The part is fitted one per side on the left and right front dampers. Checking the suspension type on the vehicle data sticker, or sending the VIN to the supplier before ordering, removes almost all ambiguity for buyers handling mixed stock.
| Parameter | Value |
|---|---|
| Product Name | Strut Bump Stop |
| Country of Origin | China |
| Bonpora Nos | 4110192 |
| OE | 1643230044 |
| Fitment | Mercedes-Benz |
| Size | Φ20xΦ63.4x70 |
| Material | Polyurethane |
| Warranty | 1 Year |
| Delivery Time | 15-30 Days |
| Packaging | Neutral Export Packaging |
| Custom Service | OEM & Custom Design Support |
The size listing Φ20 x Φ63.4 x 70 mm describes a compact front stop: a 20 mm bore that slides over the damper rod, an outer diameter of about 63.4 mm, and a free length of 70 mm. Free length is the critical dimension on a replacement buffer. A stop that is too long preloads the suspension as soon as it is fitted, reduces the available travel, and can lift the front ride height, which changes steering geometry and tyre wear. A stop that is too short lets the damper reach the end of its stroke unaided and passes the impact straight into the top mount and the body. Because Mercedes specified different stops for the steel spring and AIRMATIC versions of these platforms, measuring the removed original part and comparing bore, free length, and outer profile against the catalogue entry remains the safest way to confirm a match before a bulk order is placed.
Polyurethane is chosen ahead of ordinary foam or low grade rubber because it resists oil, ozone, road salt, and repeated compression cycling far better. It holds its shape under sustained load and stays consistent in hot, humid, and cold climates, where foam buffers tend to crumble early and cheap rubber takes a permanent set. For a distributor supplying the Mercedes SUV aftermarket, where a customer expects a suspension refresh to last for years, the longer service life of polyurethane also means fewer warranty claims and steadier repeat demand on the same part number.
Sourcing by OEM number is the most reliable route when the original marking is still legible. Mercedes-Benz prints the reference in the A 164 323 00 44 format, and the same part appears in catalogues and price lists as 1643230044, 164-323-00-44, and 164.323.00.44. All of these identify one Bonpora No. 4110192, so distributors and repeat buyers can reorder a single known specification without checking drawings on every order. For mixed orders that span several vehicle systems, the polyurethane bump stops range groups references by system and by vehicle model, which shortens the quotation workflow considerably.
If the OE number has worn away, identify the part from vehicle data instead: model, model year, engine, and above all the suspension type, since the steel spring and AIRMATIC cars take different stops. A photograph of the removed part beside a steel rule, together with the VIN, lets the supplier confirm the match before shipment. Independent workshops and Mercedes specialists that service several W164 and X164 vehicles can consolidate their bump stop stock under Bonpora numbers, keeping one part code per application and simplifying reordering across a mixed customer base.
This bump stop is manufactured in China for wholesale distribution. It runs as a catalogue item, which means the tooling already exists, dimensions stay stable between production batches, and pricing is structured for carton, pallet, and container quantities rather than single piece retail. Typical buyers include independent Mercedes specialists and workshops, European and North American importers of suspension and rubber components, distributors serving the premium SUV aftermarket, and online sellers who need a dependable source for a fast moving Mercedes reference. The chassis and suspension parts range from the same production site covers the companion items usually renewed at the same time, such as protection boots, top mounts, and spring seats, so a container can be built around complete front axle refresh kits instead of single references.
Orders ship in neutral export packaging by default, so 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 fitment can be verified on a real vehicle before a container is booked.
Each production batch is checked for free length, bore, outer profile, and material hardness. Visual inspection covers flash, voids, and surface defects that could lead to early cracking in service. Dimensional records are kept per batch, so repeat orders match the approved sample rather than drifting over time. That batch level traceability is one of the reasons the part can be offered with a 1 year warranty for export markets, and it lets a distributor answer technical questions from workshops with confidence.
Beyond the catalogue part, the same production line supports OEM and custom design work. Available options include tailored polyurethane hardness, adjusted free length, bore, or outer profile, coloured material for brand recognition, branded packaging, and private label marking. Tuners who prepare lifted or load carrying ML and GL builds sometimes request a firmer compound to suit a specific damper and spring combination, while distributors building a front axle kit usually combine several references 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 front bump stops in pairs, one for each side of the axle, and inspect the protection boot, the top mount, and the spring seat at the same time. A collapsed or crumbling stop usually indicates that the damper has been bottoming out, so check the shock absorber for fluid loss before refitting, and replace the protection boot if it is split. On the W164 and X164 front axle the stop is reached when the damper is released from its upper and lower mountings, so the work fits naturally into a front shock absorber replacement. Torque the fasteners to the figure given by Mercedes-Benz for the specific model year, and confirm that the stop is fully seated on the rod before the wheel goes back on. A wheel alignment after reassembly is standard practice on these vehicles.
A polyurethane stop should seat flat on the rod shoulder. If it does not sit flat, it will wear unevenly and may generate noise within a short mileage. Because the buffer works behind the protection boot, a light coating of the grease specified for the application makes future removal easier and reduces the chance of squeaking. When the vehicle is used for towing or is regularly driven with a heavy load, the stops should be inspected at every damper service, since repeated hard compression accelerates wear.
Catalogue listings cover the Mercedes-Benz ML-Class W164 from 2005 to 2011 with steel spring suspension, including the ML 280 CDI, ML 300, ML 320 CDI and Bluetec, ML 350, ML 420 CDI, ML 450 CDI and Hybrid, ML 500, ML 550, and ML 63 AMG, and the same front stop is listed for steel spring GL-Class X164 applications such as the GL 320 CDI and GL 350 CDI. It is the stop for vehicles without AIRMATIC. Confirm the application by model year, engine, axle position, and suspension type, or send the VIN for a precise match before ordering.
Typical signs are a sharp knock from the front over expansion joints and potholes, a sudden harshness when the vehicle is laden, and visible cracking, crumbling, or permanent compression of the old stop. Because the stop sits on the damper rod behind the protection boot, it should be inspected whenever a front shock absorber is removed. If the damper has been bottoming out, check for fluid seepage at the same time, since a failed buffer often shortens damper and top mount life.
Yes. Mercedes-Benz parts catalogues list 164 323 00 44 as a suspension strut bumper, stopper, or rubber buffer, while the workshop trade generally calls it a bump stop or jounce bumper. All of these names describe the same front axle component, and all of them map to Bonpora 4110192 in this catalogue.
Yes. OEM and custom design support is available, including adjusted polyurethane hardness, modified bore, free length, or outer profile, coloured material, and private label packaging. Delivery time is typically 15 to 30 days depending on quantity, packaging is neutral export packaging with branded options on request, and the warranty period is 1 year. Send a drawing or a sample together with the target annual volume to receive a quotation and a sampling schedule.
Send the OEM number 1643230044, the Bonpora number 4110192, the quantity, and the destination port, and the sales team will confirm specification, packing, and delivery schedule. Buyers comparing several sources can review the full auto parts line, which covers suspension, steering, and rubber components from the same factory under one catalogue.
