A Practical Guide to the 2013 BMW 135is Suspension Strut Mount
Eliminate suspension clunks and restore the sharp handling your BMW 135is is known for.
- A clunking noise over bumps is the most common symptom of a failed strut mount.
- Always replace strut mounts in pairs and get a wheel alignment immediately after the job is done.
- While replacing, inspect the strut towers for 'mushrooming' (upward bending), a known issue on the 135is chassis.
- For a durable, direct-fit upgrade, consider using the heavier-duty mount from an E90 3-Series (part #31306775098).
Signs of a Failing Strut Mount
When a strut mount wears out, it can make your performance-oriented 135is feel less precise. The rubber cracks and hardens with age, and the internal bearing can wear out. You will likely notice specific symptoms that point to a problem.
The most common sign is noise. You might hear a clunking, popping, or creaking sound from the front of the car. This is usually most noticeable when you drive over bumps or turn the steering wheel at low speeds, like in a parking lot. Other symptoms include feeling excessive vibrations through the steering wheel, a loose or unstable feeling in the steering, and uneven wear on your front tires.
Vehicle-Specific Issue: Strut Tower Mushrooming
The chassis of the BMW 135is (known as the E82) has a known weak point where the strut mounts to the car's body. A hard impact from a pothole can cause the metal of the strut tower to bend upward, a problem called 'mushrooming'. While replacing your strut mounts, it is critical to inspect this area for any deformation. Some owners install aftermarket strut tower reinforcement plates to prevent this issue.
Choosing the Right Aftermarket Strut Mount
You don't have to buy the original part from the BMW dealer. Several aftermarket brands offer quality replacements. They generally fall into three tiers.
Tier 1: Premium Aftermarket (OEM-Equivalent)
These brands are often the original equipment manufacturer (OEM) for BMW or are known to meet or exceed those standards. For the best performance and longest life, these are a safe bet. Brands like Sachs and Lemforder are often OEM suppliers. CRP (Rein) and Vaico are also well-regarded German brands that focus on OEM-quality parts.
Tier 2: Standard Aftermarket
These brands provide a great mix of quality and value for a daily driven car. Monroe is a very well-known brand in the suspension world, and their mounts are a reliable choice. They offer good performance for normal driving conditions.
Tier 3: Economy Aftermarket
These brands focus on being the most affordable option. While they will fit and function, they may not last as long as higher-tier parts, especially on a performance car like the 135is. Brands in this category include URO Parts and DEA. Some owners in forums have noted that the rubber on budget parts can wear out more quickly.
Pro Tip: A Worthwhile Upgrade
Many BMW enthusiasts choose to install the front strut mount from the E90 3-Series sedan (part number 31306775098) as an upgrade. This part is reportedly made of steel instead of aluminum, making it stronger and more durable. It is a direct fit for the 135is and can provide extra peace of mind.
Cost of New Aftermarket Strut Mounts
The cost for a new aftermarket strut mount for your 2013 BMW 135is can vary based on the brand's quality tier.
| Part Type | Price Range (Per Part) |
|---|---|
| New Aftermarket | $19.74 - $82.62 |
| New OEM (Dealer) | $104.00 - $153.00+ |
Frequently Asked Questions
Should I replace strut mounts in pairs?
Yes, absolutely. You should always replace both the left and right front strut mounts at the same time. This ensures your suspension is balanced, which is critical for proper handling and safety.
Do I need a wheel alignment after replacement?
Yes, a four-wheel alignment is mandatory after replacing the strut mounts. The strut mount is a key part of your car's suspension geometry. Skipping the alignment will lead to poor handling and will wear out your tires very quickly.
Can I reuse the old bolts?
It is strongly recommended to use new hardware. Many of the nuts and bolts involved are single-use stretch bolts and are designed to be replaced to ensure safety and proper torque.
Is this a good DIY job?
This is an advanced DIY job. The most dangerous part is the need to compress the coil spring, which is under extreme tension and requires a special tool. If you are not experienced, it is safer to have a professional mechanic do the work.
Technical Specifications
OEM Part Numbers: 31336760943 31306775098
The strut mount for the 2013 BMW 135is is a top-hat style mount that contains an integrated bearing for steering pivot and rubber insulation for vibration damping. It attaches to the chassis via three top bolts.
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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.
- BMW 135is: