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BMW introduced the X5, internal code E70, in 2006 as the second generation of its premium Sports Activity Vehicle, and added the X6, internal code E71, in 2008 as the Sports Activity Coupe derived from the same platform. Both model families share a double joint spring strut front axle, a layout that combines precise steering response with high load capacity. Inside this assembly a small polyurethane component performs an important protective task: the front strut bump stop, listed in the BMW parts book under OE number 31336776389. Bonpora supplies this reference under Bonpora No. 4110225, molded in polyurethane with a bore of 17 mm, an outer diameter of 56 mm, and a height of 16 mm. This page is written for importers, parts distributors, and suspension workshops that source BMW parts by OEM number.
In the BMW catalog, 31336776389 appears as the guide support lower part of the front shock absorber mount, a flat disc that sits inside the front strut assembly of the X5 E70 and X6 E71. The disc centers the damper rod within the dust sleeve, cushions the frequent low amplitude compressions, and shields the top mount and rod seal before the main progressive bump stop engages. When the disc hardens, powders, or collapses with age, drivers notice clunking noises over rough roads and the front dampers tend to wear earlier than expected. Related suspension components can be found in our shock absorber parts catalog.
BMW assigns the number range 31 33 to front axle spring strut components, so the leading digits of 31336776389 already tell buyers where the part belongs. The guide support lower part sits inside the front strut mount stack of the X5 E70 and X6 E71, sliding over the damper rod between the dust sleeve and the supporting hardware. The geometry defined by BMW is a center bore of 17 mm that fits over the rod guide, an outer diameter of 56 mm that registers against the surrounding sleeve, and a thickness of 16 mm that sets the free gap in the stack. Because the disc is flat rather than tapered, it works as both a spacer and a cushion, and its polyurethane compound stays more stable under repeated compression than a basic rubber washer.
On the E70 and E71 front axle, compression travel is managed in stages. The tall progressive main bump stop handles deep events such as potholes and heavy loads, while the lower guide support disc absorbs the short, frequent movements of everyday driving. The disc also keeps the dust sleeve centered on the rod, which prevents the folded boot from rubbing against the chrome surface and tearing. The two parts work as a pair: one protects the damper at full compression, the other protects the rod, boot, and mount in normal service.
The table below lists the parameters of this reference as manufactured by Bonpora. Buyers can use these values for dimension checks before dispatch or for cross comparison with the original part removed from the vehicle.
| Parameter | Value |
|---|---|
| Product Name | Strut Bump Stop (Guide Support Lower Part) |
| Bonpora No. | 4110225 |
| OE Number | 31336776389 |
| Fitment | BMW X5 (E70), BMW X6 (E71), front axle |
| Size | Bore 17 mm x Outer diameter 56 mm x Height 16 mm |
| Material | Polyurethane |
| Country of Origin | China |
| Warranty | 1 Year |
| Packaging | Neutral Export Packaging |
| Delivery Time | 15-30 Days |
| Custom Service | OEM and Custom Design Support |
Distributors that build a wider suspension program for European and American vehicles can browse our polyurethane bump stops category, which covers additional brands, axle positions, and dimensions.
Trade buyers usually start a suspension parts search from the chassis code, so the table below summarizes the confirmed application range of OE 31336776389. The part is assigned to the front axle of both model families, and within each family petrol, diesel, and performance variants share the same front strut layout. As a general practice, buyers should confirm the OE number against the vehicle identification number before placing an order, because BMW modified suspension details across production years and regional versions.
| Model | Chassis Code | Production Years | Axle Position |
|---|---|---|---|
| BMW X5 | E70, including LCI update | 2006-2013 | Front, left and right |
| BMW X6 | E71, including LCI update | 2008-2014 | Front, left and right |
The E70 X5 generation covered six cylinder petrol and diesel engines, V8 petrol engines, and the M variant, while the E71 X6 mirrored these drivetrains and added the ActiveHybrid X6. Because the front axle architecture is common across these variants, the guide support reference stays the same, which simplifies stock planning for distributors serving mixed BMW fleets.
Polyurethane ages through heat cycles, moisture, and ozone exposure, and a guide support disc usually shows its condition clearly once the dust sleeve is opened. Typical findings include the following:
Workshops normally inspect the bump stop and guide support whenever a front shock absorber, dust cover, or top mount is replaced, because the labor to open the assembly has already been paid. Replacing the disc at the same time restores the designed clearance in the strut stack and protects the investment in the new damper. For fleets based on the X5 E70 and X6 E71, keeping a small stock of these low cost references avoids repeat visits for the same axle.
Professional buyers search by OEM number because it removes ambiguity. A query for 31336776389 points to exactly one part with defined dimensions, one axle position, and one vehicle application, which shortens quotation cycles and reduces returns. Bonpora recommends three checks before confirming an order: verify the chassis code of the vehicles in question, confirm the front axle position, and compare the removed part against the values in the specification table. When the numbers match, the reference can be ordered with confidence.
Original equipment buffers of this class are molded from microcellular foam or elastomer compounds, and the aftermarket offers both rubber and polyurethane alternatives. Polyurethane brings practical advantages for a guide support disc: higher tear resistance at the thin edges, lower compression set under repeated load, and stable stiffness across a wide temperature range. Rubber remains suitable for many buffers, but for a flat disc that is compressed millions of times at low amplitude, the fatigue behavior of polyurethane gives distributors a dependable option at a competitive cost.
Bonpora produces suspension buffers in dedicated polyurethane molding lines, and each batch is checked for hardness, bore diameter, outer diameter, and height before packing. The production team controls mixing ratio and curing time so that hardness stays within the specified band, because a disc that is too soft collapses early and a disc that is too hard transmits noise into the body. Dimensional sampling follows the values that BMW defined for 31336776389, so replacement parts mount without rework.
Many buyers serve markets where vehicle fleets use modified suspension, or where an old reference is no longer available from the original supplier. Bonpora offers OEM and custom design support for these cases: customers provide a drawing, a sample, or the OE number and target dimensions, and the engineering team proposes material hardness, mold design, and a sampling plan. Typical custom projects include discs with different thickness, tapered progressive buffers, and pads with special bore sizes for dampers from other suppliers.
Every order passes a documented inspection flow: incoming material verification, first article inspection against the drawing, in process hardness checks, and final dimensional sampling before packing. Batch records allow traceability for distributor audits, and packaging is designed so that polyurethane parts do not deform during container transport. This routine supports the 1 year warranty that applies to the product.
Bonpora ships this reference in neutral export packaging, with poly bag and standard carton as the default and customer labels available on request. Delivery time is 15 to 30 days depending on order quantity and production schedule. Mixed loading with other suspension references is possible, which helps distributors reach a full container with a balanced range of bump stops, guide supports, and related buffers.
The number covers the guide support lower part of the front shock absorber mount on the BMW X5 E70, produced from 2006 to 2013, and the BMW X6 E71, produced from 2008 to 2014, including their LCI updates. Petrol, diesel, hybrid, and M variants share the same front axle reference. Buyers should confirm the OE number against the VIN before ordering.
Yes, in principle the disc can be renewed on its own, and many workshops do this when the damper still passes inspection. The condition of the rod surface and dust sleeve should be checked at the same time, because a collapsed disc often allows the boot to rub the rod, and if the damper shows oil leakage, a complete strut service set is more economical.
Yes. Bonpora provides OEM and custom design support, working from drawings, samples, or target dimensions. The service covers material hardness selection, mold development, and sampling before volume production, which suits distributors that need specific sizes for particular vehicle populations.
The standard offer is neutral export packaging with customer labeling available on request, a 1 year warranty, and a delivery time of 15 to 30 days. Mixed container loading with other suspension parts is supported for distributors building a complete program.
Distributors, wholesalers, and suspension workshops that need Bonpora No. 4110225 or a custom equivalent are welcome to send an inquiry with the required quantity and destination port. The sales team replies with a quotation, packing plan, and production schedule. Please reach us through the contact information page.
