Lexus Strut Bump Stop 48341-48050 | OEM Replacement Supplier & Custom Manufacturer

The Lexus strut bump stop 48341-48050 is the rear axle spring bumper fitted over the shock absorber rod of the Lexus RX crossover family. Genuine Lexus catalogues list the part as Rear Spring Bumper No.1 and apply it to the RX330, the RX350 and the RX400h hybrid. When the rear suspension reaches full compression, this buffer engages and absorbs the final stage of the impact before the axle meets the chassis, protecting the damper, the spring seat and the body mounts. Because the RX is a vehicle that frequently carries passengers, luggage and towing loads, rear buffers in this family work hard and are replaced regularly in workshops. Bonpora manufactures this part in China as a direct-fit replacement under reference 4110214, and also supports custom polyurethane designs for importers, distributors and workshop chains. This page summarises the specification, verified fitment, cross references and commercial details that professional buyers need.

What the 48341-48050 Does in the Rear Suspension

The Lexus RX uses coil springs and gas dampers on the rear axle. A coil spring can be compressed beyond its design travel when the vehicle hits a deep pothole, carries a heavy load, or descends quickly onto a compression event. The bump stop is the engineered final cushion for that event. Mounted on the rear damper rod, the 48341-48050 compresses progressively, converting a hard metal-to-metal impact into a controlled deceleration curve.

Three functions follow from this role. First, it limits suspension travel and prevents the damper from bottoming out, which is the main cause of shock absorber seal failure. Second, it protects the coil spring, the spring insulator and the strut mount from overload damage. Third, it keeps rear ride behaviour consistent: a healthy buffer degrades gently, while a missing one makes every full-compression event audible and harsh. Workshops that fit new dampers without checking the buffers often see the new dampers fail early, which is why suspension specialists recommend inspecting and usually replacing the bump stop whenever the rear dampers are renewed.

Lexus Strut Bump Stop 48341-48050 Specification

Purchasing teams normally start with a dimensional check before comparing prices. The reference part below is manufactured to the original drawing tolerances and is intended as a direct-fit replacement for the applications listed under OE 48341-48050.

What the Dimensions Mean

The stated size Φ21 x Φ57 x 84 describes a cylindrical microcellular buffer. The 21 mm centre bore slides over the rear damper rod, the 57 mm outer diameter determines how much compression travel is absorbed before the suspension bottoms out, and the 84 mm free height sets the clearance available under full bump. These three values identify the part far more reliably than a photograph does, because several buffers in the RX parts bin look alike but differ in bore or height. Confirm all three against the removed part, or against the parts diagram for the specific chassis code, before releasing an order.

Fitment and OE Number Cross Reference

Bump stops are frequently ordered by OE number rather than by vehicle description, because one buffer design often covers several model years and related platforms. The genuine Lexus catalogue applies 48341-48050 to the rear spring and shock absorber assembly of the following vehicles:

The number also carries a supersession history that buyers should recognise when quoting older vehicles: early references 48341-0E030 and 48341-48020 were consolidated into 48341-48050, so the current number covers stock requests raised under any of the three. Required quantity per vehicle is two, one for each rear damper, and many aftermarket sources sell the part in pairs.

European aftermarket catalogues that map the same geometry extend the family across the Toyota side of the platform. Those listings connect the buffer to the rear axle of the Toyota Harrier (the Japanese-market twin of the RX), the Highlander and Kluger SUV ranges, and the Venza crossover:

Because catalogues differ in how far they extend each reference, treat the table above as a sourcing guide rather than a guarantee. Professional practice is to confirm the OE number on the removed part, or to match the chassis code and the three key dimensions, before committing to an order for the Toyota-badged applications. An experienced auto parts supplier will return a dimensional drawing, a material specification and photographs together with the quotation, so the buyer can verify the match in a single message.

Aftermarket Cross References

Independent aftermarket brands reference the same geometry under their own numbers, which is useful when a distributor wants to position the part against a known catalogue line:

When Should a Rear Strut Bump Stop Be Replaced?

Bump stops fail gradually, so the symptoms arrive in stages. Recognising them early protects the more expensive components around the buffer.

Typical Symptoms

The most common report is a knocking or thudding noise from the rear axle over speed bumps, driveways and potholes, caused by the suspension reaching full travel without an effective cushion. Drivers may also notice a harsh, jarring impact when the vehicle is loaded and passes a sharp compression event. Aged buffers often show visible crumbling, cracking or permanent compression set when the rear wheel is removed, and buffers that have been soaked by a leaking damper lose their cellular structure and stiffen. Any of these conditions justifies replacement.

Replacement Advice

Replace the buffers in pairs so both rear corners retain the same progressive rate, and inspect the damper rod and dust boot at the same time. The buffer is a low-cost item relative to the labour of the job, so most workshops fit new buffers whenever rear dampers are replaced. For fleets and distributors in markets where the RX and its Toyota twins are common, stocking the 48341-48050 in pairs reduces order fragmentation and keeps this fast-moving reference available off the shelf.

Polyurethane vs Rubber Bump Stops

Original buffers were commonly moulded from microcellular rubber. Microcellular polyurethane (MPU) has largely replaced it in replacement programmes because it holds its shape under repeated compression and resists oil, ozone and road-salt exposure.

The Bonpora 4110214 is moulded in microcellular polyurethane with a density profile tuned to the original rate curve, so the buffer stays soft at the start of the stroke and stiffens progressively toward full compression. Distributors who need a different rate, height or bore for a local programme can source it through the polyurethane bump stop range, which covers the full RX, Harrier and Highlander buffer family plus custom geometries.

OEM Replacement Supply and Custom Manufacturing

Bonpora produces suspension buffers in China for overseas distributors, wholesale chains and workshop groups. Standard catalogue items such as the 48341-48050 ship from existing tooling, while project buyers can order against a drawing or a sample. Typical custom requests include modified heights, alternative bore diameters, different hardness grades and private-label packaging. Design support runs from dimensional drawing and material specification through to mould making and first-article inspection, and the team accepts development starting from a physical sample when no drawing exists.

Quality Control and Export Details

Each production batch is checked for bore, outer diameter, free height, density and compression behaviour before packing. Goods leave the factory in neutral export packaging without third-party branding, so distributors can place their own labels on the cartons. The standard commercial terms are a 1-year warranty, a delivery window of 15 to 30 days depending on quantity, and mixed-loading of several references in one container for buyers who consolidate a suspension programme. Buyers planning a private range of buffers for the RX family can start from the custom parts service and combine catalogue items with project-specific moulds.

Who Buys This Part

The 48341-48050 moves through three main channels. Independent parts distributors quote it against the OE number when RX owners ask for a lower-cost alternative to the genuine part. Suspension specialists add it to damper and coil spring kits for the 2004 to 2009 RX range. Export traders in the Middle East, Africa, Southeast Asia and South America source it for markets where the RX, Harrier and Highlander fleets are large and vehicle ages are rising, which keeps replacement demand steady.

Frequently Asked Questions

What vehicles does the 48341-48050 bump stop fit?

The genuine catalogue applies it to the rear axle of the Lexus RX330 (2004–2006), RX350 (2007–2009) and RX400h (2006–2008). Aftermarket catalogues extend the same geometry to the rear axle of the Lexus RX300 late build, the Toyota Harrier, the Highlander and Kluger ranges and the Venza. Confirm the chassis code and dimensions before ordering for the Toyota-badged applications.

What is the difference between 48341-48050 and 48341-48020?

They are the same part in supersession order. Toyota and Lexus consolidated earlier references 48341-0E030 and 48341-48020 into the current number 48341-48050, so a buffer sold under any of the three references serves the same applications. Quote the number printed on the removed part and check the supersession chain if the catalogue shows an older reference.

Can I order custom sizes, hardness or packaging?

Yes. Bonpora supports OEM and custom design service for polyurethane bump stops. Provide a drawing, the three key dimensions or a physical sample, and the engineering team will confirm tooling, material grade and hardness options. Private-label packaging is available for distributors, and mixed references can be loaded in the same shipment.

What are the warranty, lead time and packing terms?

The standard offer is a 1-year warranty, delivery in 15 to 30 days depending on order quantity, and neutral export packaging suitable for private labelling. Quotations normally include a dimensional drawing and photographs of the finished part, and samples can be arranged for evaluation before bulk production.

Request a quotation: send the OE number 48341-48050, the required quantity and the destination port, and the Bonpora sales team will reply with pricing, drawings and packing details. Buyers who need related buffers for the RX, Harrier or Highlander families can request the full suspension buffer list for the platform in the same message.