A Practical Guide to the 2004-2013 Audi S4 CV Joint Boot Kit
Grease on your wheels? Clicking on turns? Here's what you need to know about replacing your S4's CV boots.
- The first sign of failure is grease on the inside of your wheel; repair it immediately to avoid a more costly CV joint replacement.
- Use an OEM-supplier brand like GKN Loebro for the boot kit; your original Audi axles are better than most cheap aftermarket replacements.
- A clicking noise when turning means the CV joint is already bad; replacing just the boot will not fix the noise.
- Verify the exact part for your S4's year (B6/B7 vs. B8) and for inner/outer/front/rear location before buying.
Signs of a Failing CV Boot
The first sign of a problem is usually visual. You will see dark, thick grease splattered on the inside of your wheel, on the suspension parts, or on the brake components. This means the boot has a tear or crack. If you catch it at this stage, you can often save the CV joint itself by just replacing the boot.
If you wait too long, the CV joint will get damaged. You will then hear a rhythmic clicking or popping sound when you make sharp, slow turns, like in a parking lot. This clicking noise means the joint is already worn out, and simply replacing the boot won't fix it. At this point, the entire CV joint or axle shaft needs replacement. You might also feel vibrations during acceleration, which often points to a problem with the inner CV joint.
Choosing the Right Aftermarket Boot Kit
When shopping for a CV boot kit, quality matters. Your S4's original axles are very well-made. It is almost always better to replace a torn boot on a factory axle than to replace the entire axle with a cheap aftermarket one. Many cheap aftermarket axles are known to cause vibrations and fail early.
Aftermarket Brand Quality Tiers for Audi S4
| Tier | Brands | Description |
|---|---|---|
| OEM Supplier | GKN Loebro | GKN is the original manufacturer for Audi's CV axles and boots. Choosing a GKN Loebro kit gets you the same part the dealer sells, just without the Audi logo, for less money. This is the most recommended option by S4 owners. |
| Premium Aftermarket | CRP (Rein) | CRP/Rein kits are known for being complete and high-quality. They include the correct type of OE-spec grease and all the necessary clamps and hardware for the job. This is a trusted choice if GKN is not available. |
| Standard Aftermarket | Vaico, Beck Arnley | These brands offer a cost-effective solution. They meet basic fit and function requirements. While they can be a good budget option, they may not have the same long-term durability as an OEM supplier part, especially on a high-performance car like the S4. |
Common Ordering Mistakes
The 2004-2013 S4 covers two different generations: the B6/B7 (2004-2009) with a V8 engine and the B8 (2010-2013) with a supercharged V6. 🎬 See this step-by-step guide for B8 generation CV boot repairs. Parts are not always interchangeable. Always verify the part fits your specific year. Also, check if you are ordering an inner or outer boot kit for the front or rear axle, as they are all different. Some B8 models have an optional Sport Differential, which can change the rear axle parts required. Double-check your vehicle's specifications before ordering.
Known Issues, Recalls, and TSBs
CV boot failure is a common maintenance item on Audis due to age, heat, and the boots flexing. The inner front boots can be exposed to significant heat from the engine and exhaust, while the outer boots see the most stress from steering movements. There are no specific recalls or Technical Service Bulletins (TSBs) from the NHTSA for CV joint boot failure on the 2004-2013 Audi S4. Any recalls found for these model years are typically for other components.
Frequently Asked Questions (FAQ)
Is it okay to just replace the boot if my axle is clicking?
No. A clicking sound means the CV joint is already damaged from lack of grease and contamination. At this stage, replacing only the boot is a waste of time and money. The noise will not go away, and the joint will eventually fail completely. You will need to replace the entire CV joint or the complete axle shaft.
🎬 Watch: A complete walkthrough on replacing the CV axle yourself.Can I do this job myself?
This is a possible but messy and moderately difficult DIY job. It requires safely lifting the car, removing the wheel, and detaching suspension components to remove the axle. You will also need special tools like a large hex socket for the axle bolt and a 10mm triple-square socket for the inner joint bolts. Many experienced DIYers find it frustrating due to the thick, sticky grease.
Should I replace the whole axle or just the boot?
If the joint is not clicking or vibrating, just replace the boot using a high-quality kit like GKN. The original Audi axles are stronger than most aftermarket replacements. Replacing the whole axle is often easier but can be more expensive. If you do replace the whole axle, investing in a quality brand is critical to avoid new problems like vibrations.
How much should the repair cost?
A CV boot kit itself is not expensive. However, labor is where the cost is. Expect a repair shop to charge for 2-3 hours of labor. Total cost at a shop can range from around $200 to over $400, depending on the shop's labor rate.
Helpful Videos
Technical Specifications
OEM Part Numbers: 8E0498203C 8K0498201B 4E0498201 8K0598203A 8K0598201C
Kit typically includes one rubber or thermoplastic boot, two clamps, and a packet of molybdenum disulfide (MoS2) grease. Some kits may also include a new axle bolt and circlips.
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.
- Audi S4: