Mazda Strut Bump Stop BR5G-34-111A: OEM and Custom Polyurethane Replacement Parts from China Factory

Mazda Strut Bump Stop BR5G-34-111A: What This Front Jounce Bumper Does

The Mazda strut bump stop with OE number BR5G-34-111A is the front axle jounce bumper used on the Mazda 3 and Mazda Axela. It sits on the piston rod of the front shock absorber and works as a progressive secondary spring. Under normal driving it rides quietly on the rod, almost invisible. When a pothole, a speed hump or a heavy load drives the strut deep into compression, the bumper is the last element that keeps metal from meeting metal.

Our production unit carries Bonpora No. 4110165. It is a direct replacement for the original rubber part, moulded from engineering polyurethane with a bore of 18 mm, an outer diameter of 50.8 mm and a free height of 64.5 mm. Buyers who search for the OEM number, for a Mazda 3 front bump stop, or for a custom suspension bump stop supplier usually want the same three things: correct dimensions, repeatable quality, and a factory that can quote a custom mould without a long delay.

BR5G-34-111A Specifications and Material Data

The 18 mm bore is the dimension to check first. It is sized for the original Mazda piston rod diameter, so a bumper that fits an aftermarket damper with a thicker rod may need a different bore. Where a vehicle has been converted to coilover suspension, measure the rod before ordering and tell us the value, because we can mould a range of bore sizes on the same outer profile.

Vehicle Fitment: Mazda 3 and Axela BK and BL

BR5G-34-111A is listed in the Mazda front suspension mechanism diagram under item number 34111, described as Bumper, Bound, with a required quantity of two per vehicle. Third party catalogues cross reference the same number for the following applications:

Engine coverage reported by aftermarket catalogues for these applications runs from the 1.6 litre and 2.0 litre petrol units up to the 2.3 litre MZR and the turbocharged 2.3 MPS variants, in the range of roughly 105 to 267 hp depending on market. Because the bumper is a chassis component rather than an engine component, the same part is used across those engine options.

Why the model year matters more than the model name

Mazda changed the front bump stop several times across the life of the 3. BP4K-34-111C covers the early BK cars and was itself superseded twice from BP4K-34-111A through BP4K-34-111B. BBM2-34-111 appears in later listings. For the third generation, B45A-34-111A, B45G-34-111A and BCKE-34-111A are separate numbers again. The outer profile and the free height differ between these groups, so a part sold as a generic Mazda 3 bump stop may not match your strut.

The safest way to confirm BR5G-34-111A

Three checks settle the question quickly. First, read the number stamped on the old bumper, or look it up by VIN in the Mazda electronic parts catalogue for the front suspension mechanism group. Second, measure the free height and the bore of the part you remove and compare them with the 64.5 mm and 18 mm figures above. Third, confirm the fitting position: this is a front axle part, and rear axle bump stops use different numbers.

Polyurethane Versus Original Rubber

The original bumper is a rubber moulding. Rubber works well when it is new, but it takes a set over time, absorbs oil and road salt, and eventually cracks or crumbles. Once the bumper has lost its height, the strut bottoms out earlier on every compression, and the driver feels it as a hard knock over speed humps and broken asphalt.

Polyurethane is not automatically better in every respect, and we do not claim that it is. It is stiffer for the same shape, which changes the way the suspension feels in the last part of its travel. For a daily driven car the difference is small and most drivers notice only that the knock over sharp bumps has gone. For a car used on rough roads or carrying loads regularly, the longer service life is the main benefit. Hardness can be specified to suit the application.

How to Use the OEM Number to Source the Right Part

Cross reference numbers are the fastest route from a workshop job card to a purchase order, but they need to be read correctly. The same bumper is traded under several different codes, and not all of them are interchangeable with each other.

The middle digits carry meaning in the Mazda system. The 34 group is the front suspension and steering family, the 111 block identifies the bound bumper, and the letter suffix marks the revision level. A trailing A, B or C is not decoration: it means the shape or the compound was changed, and an earlier letter will not always substitute for a later one.

What to send with an enquiry

A clear enquiry gets a faster answer. Useful details are the OEM number, the vehicle model and year, the bore, outer diameter and free height, the quantity per vehicle, and the annual volume you expect. If the part is for a modified car rather than a standard one, say so, because the required height and hardness will differ from the catalogued specification.

Common Symptoms of a Worn Front Bump Stop

A collapsed or missing front bumper does not usually fail suddenly. The signs build up over months.

• Heavy knocking or a dull thud from the front when crossing speed humps or sharp ridges.
• A metallic bottoming out sensation on compression that was not present when the car was newer.
• Visible crumbs of rubber or polyurethane on the shock absorber rod or inside the strut tower area.
• A bumper that has lost height, or that has cracked around the bore, when inspected with the strut removed.
• A noticeably harsher ride over broken surfaces even though the shock absorbers still pass a bounce test.
• Uneven wear on the upper spring seat or the dust cover, caused by a collapsed bumper letting the strut travel further than designed.

Bump stops are normally replaced as part of a strut overhaul rather than on their own, because the labour to reach them is the same either way. If the strut is already apart, fitting a new bumper costs very little extra.

Custom and OEM Production for Wholesale Buyers

For distributors and workshops that purchase in volume, the standard BR5G-34-111A profile is only the starting point. We produce suspension bump stops for on road and off road applications in a wide range of sizes, and the same tooling approach applies here.

• Hardness selection from 70A to 95A to match the ride you want.
• Custom bore, outer diameter and free height, including progressive and multi rate internal profiles.
• Moulded or laser marked part numbers, and private label packaging.
• Neutral export packaging as standard, with brand packaging available on request.

Tooling for a new bumper profile typically needs a drawing or a sample. If you have a worn original Mazda bumper, sending it to us is often the simplest way to start, because we can measure the free height and the bore directly and work from the failure mode as well as the drawing. The wider range of shock absorber components we supply is listed under shock absorber parts, and the full bump stop programme sits under polyurethane bump stops.

Quality Control Before Shipment

Every batch is checked before it leaves the factory. Dimensional inspection covers the bore, the outer diameter and the free height against the drawing tolerance. A compression test confirms the load curve of the moulding. A visual check looks for flow lines, voids and short fills around the inner bore, the area most likely to show a moulding defect.

FAQ

Is BR5G-34-111A the correct front bump stop for my Mazda 3?

It is the front axle jounce bumper for Mazda 3 and Axela BK and BL applications, including MPS and Mazdaspeed variants, with two required per vehicle. Later generations use different numbers. Confirm by VIN or by reading the number on the part you are replacing.

Are the numbers BR5G-34-111A and BR5G34111A the same part?

Yes. They are the same Mazda number written with and without separators. FEBEST MZD-MZ323F is an aftermarket reference for the same application, while BP4K-34-111C and BCKE-34-111A belong to other Mazda 3 generations and should not be treated as interchangeable.

Can you make this bumper in a different height or hardness?

Yes. The bore, outer diameter and free height can be adjusted, and hardness can be specified from 70A to 95A. Custom work is usually quoted from a drawing or a physical sample, and a first article sample can be supplied for fitting checks before mass production.

What is the minimum order and delivery time?

Delivery time for standard production is 15 to 30 days. Minimum order quantity depends on whether the profile already exists in our tooling or needs a new mould, so please send the specification and the volume you plan to buy and we will confirm both figures.

Request a Quotation for BR5G-34-111A

Send us the OEM number, the quantity you need and the market you serve, and we will reply with price, tooling status and lead time. Full contact details are on our contact information page, and you can also send a drawing or a sample photo for a technical review before you commit to an order.