2006-2008 Lexus RX400h Suspension Strut Bellows Replacement and Information
Learn how to protect your RX400h's expensive struts by replacing a simple, inexpensive part.
- A torn strut bellow will cause the entire strut assembly to fail over time by exposing it to dirt and moisture.
- KYB is the OEM-equivalent brand for a quality repair; their kits may require reusing a piece of the original mount.
- Replacement is labor-intensive and requires a dangerous spring compressor, so professional installation is strongly recommended.
- There are no recalls or TSBs from Lexus for this specific part on the 2006-2008 RX400h.
Is Your RX400h Strut Bellow Failing?
The strut bellow is a wear item made of rubber or polyurethane. Over time, it becomes brittle from exposure to the elements and can crack, tear, or fall apart completely. Unlike a failed strut, a torn bellow won't immediately change how your RX400h drives, but it sets the stage for much more expensive repairs down the road.
Symptoms of a Bad Strut Bellow
- Visible Damage: The most obvious sign is seeing that the boot is cracked, ripped, or missing. You can often spot this by looking into the wheel well at the suspension components.
- Suspension Noises: While a torn boot itself is silent, it allows the strut to wear out prematurely. Once the strut is damaged, you may hear clunking, rattling, or knocking sounds when driving over bumps. This indicates the damage has progressed beyond just the bellow.
- Leaking Strut: If you see oily fluid on the body of the strut, it means the main seal has failed, a direct consequence of being exposed by a damaged bellow.
A Torn Bellow Leads to Strut Failure
Ignoring a torn strut bellow is not recommended. Once the protective boot is gone, road debris will scratch the strut's piston rod, which then shreds the main oil seal. This causes the strut to leak its hydraulic fluid, losing its ability to dampen bumps. The result is a bouncy, uncontrolled ride and the need to replace the entire, much more expensive, strut assembly.
Choosing the Right Aftermarket Strut Bellow
For the 2006-2008 Lexus RX400h, you have a couple of quality tiers to choose from when it comes to aftermarket bellows.
Tier 1: OEM-Equivalent Brands
KYB: KYB is widely known to be the original equipment manufacturer (OEM) for Lexus and Toyota suspension parts. Choosing a KYB strut bellow (part numbers SB102 for the front, SB105 for the rear) is the closest you can get to the original factory part in terms of material quality and fit. Forum users and mechanics agree that KYB offers excellent durability. If you want to maintain the original performance and longevity, KYB is the recommended choice.
Installation Note for KYB Bellows: Some KYB replacement bellows for the RX400h are designed differently from the original part. The factory bellow is often a single piece integrated with the upper spring insulator. The KYB kit may require you to carefully cut the old bellow away from the original insulator and reuse the insulator portion with the new KYB boot.
Tier 2: Economy Brands
Skyward: Skyward is a budget-friendly brand. While offering a significant cost saving, there is very little public information available regarding the quality, fit, or durability of their suspension components. This brand may be a suitable choice for a vehicle owner on a strict budget who needs to get the strut protected, but long-term performance is unknown compared to established brands like KYB.
Known Issues, Recalls, and Service Bulletins
There are no specific recalls or Technical Service Bulletins (TSBs) from Lexus or the NHTSA related to the suspension strut bellows for the 2006-2008 RX400h. While major recalls were issued for this vehicle concerning the hybrid inverter system, the suspension components were not part of any widespread safety campaign.
| Part/Service | Estimated Cost (Per Pair) |
|---|---|
| New Aftermarket Bellows | $22 - $32 |
| Shop Labor | $280 - $415 |
| Total Estimated Cost | $302 - $447 |
Note: Labor costs are high because replacing the bellow requires the same procedure as replacing the entire strut assembly. An alignment is also recommended after the job.
Frequently Asked Questions (FAQ)
Can I just ignore a torn strut boot?
You can, but it's not wise. A torn boot offers zero protection to the strut's most sensitive parts. Driving with a torn boot will lead to the premature failure of the entire strut assembly, which is a much more expensive part to replace. It's best to replace the boot as soon as you notice it's damaged.
Do I need a wheel alignment after replacing strut bellows?
Yes. The replacement process requires removing the strut assembly from the vehicle. This directly affects your vehicle's suspension geometry. A four-wheel alignment is necessary after the parts are reinstalled to ensure proper handling, safety, and to prevent rapid, uneven tire wear.
Should I replace just the bellow or the entire strut assembly?
This depends on the condition of your struts. If your RX400h has high mileage (over 100,000 miles) and the struts are original, it is often more cost-effective to replace the entire strut assembly. The labor cost is the same for both jobs, so if the struts are nearing the end of their life anyway, replacing the complete assembly saves you from paying for the same labor twice.
Is replacing a strut bellow a good DIY job?
This is an advanced DIY job, rated 4 out of 5 for difficulty. The process requires disassembling the strut, which involves using a special tool called a spring compressor. This tool can be extremely dangerous if not used correctly. For safety reasons, this job is best left to an experienced mechanic unless you have the proper tools and experience with suspension work.
Technical Specifications
OEM Part Numbers: 48540-49315
Aftermarket Front Bellows Part Number: KYB SB102. Aftermarket Rear Bellows Part Number: KYB SB105.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Lexus RX400h:
- 🛍️ Shop This Part
- Is Your RX400h Strut Bellow Failing?
- Symptoms of a Bad Strut Bellow
- A Torn Bellow Leads to Strut Failure
- Choosing the Right Aftermarket Strut Bellow
- Tier 1: OEM-Equivalent Brands
- Tier 2: Economy Brands
- Known Issues, Recalls, and Service Bulletins
- Frequently Asked Questions (FAQ)
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