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2022-2024 Rivian R1S Splash Guards & Mud Flaps: Damage, Replacement, and Options

A detailed guide to the R1S's factory underbody splash guards and popular aftermarket mud flap upgrades, focusing on common damage and replacement.

5 minutes to read 2022-2024 Rivian R1S
Difficulty
1/5
Est. Time
0.75 hrs
DIY Doable?
✅ Yes
Shop Labor
$70 - $200
Used OEM Price
$40 - $75
⚠️ Drivable, but... — Yes, but a loose or dragging guard can be torn off at speed, potentially becoming a road hazard for other drivers. It should be removed or secured as soon as possible.
Key Takeaways
  • The term 'splash guard' can mean either the factory underbody shield (like PT00048748) or an optional accessory mud flap; Rivian does not sell its own accessory mud flaps.
  • Failure is always physical damage (cracks, breaks) from impacts, resulting in scraping or rattling noises.
  • Installation of aftermarket mud flaps is a simple, no-drill DIY job that takes less than an hour using factory mounting points.
  • When buying a used guard, the most important check is for cracks around the mounting holes, as this will prevent a secure fit.
On a 2022-2024 Rivian R1S, the terms 'mud guard' or 'splash guard' can refer to two distinct types of parts. First are the factory-installed underbody splash shields, which are rigid plastic panels designed to protect critical components like the battery and subframe from road debris and water. An example is the OEM part PT00048748, the 'Right Rear Underbody Battery Splash Guard'. Second are accessory-style 'mud flaps,' which are typically flexible or semi-rigid flaps installed in the wheel wells behind the tires. These are primarily designed to prevent tires from throwing mud, rocks, and water onto the vehicle's side panels and doors, reducing paint chips and keeping the vehicle cleaner. While the factory shields offer underbody protection, they provide minimal defense against side spray, leading many owners to install aftermarket mud flaps for better paint preservation, especially when driving on gravel or in harsh weather.

Understanding Mud Guards vs. Mud Flaps on the R1S

When discussing mud protection for the 2022-2024 Rivian R1S, it's important to distinguish between two different components. Your R1S comes from the factory with hard plastic underbody splash shields. These are essential protective panels that cover the vehicle's battery and other sensitive undercarriage components. They are not what most people think of as traditional mud flaps.

Separately, there are accessory mud flaps (often called splash guards). These are the vertical flaps that mount inside the wheel wells to stop spray from the tires. Rivian does not offer its own official accessory mud flaps, which has created a large market for aftermarket solutions. This guide covers the symptoms, inspection, and replacement of both types of parts.

Symptoms of Failure

Failure of either the factory underbody shields or accessory mud flaps is almost always due to physical damage. Since these parts are not connected to any vehicle electronics, there will be no warning lights or diagnostic codes.

  • Scraping or Dragging Noises: The most common symptom is a scraping sound, especially when driving over bumps, dips, or uneven roads. This indicates a piece of the plastic shield or flap is hanging loose and making contact with the ground.
  • Rattling or Vibrating Sounds: A loose or partially detached guard can rattle or vibrate at speed as air passes over it. This often points to broken or missing mounting clips or screws.
  • Visible Damage: A visual inspection is the best diagnostic tool. Look for cracks, splits, large holes, or sections that are completely broken off. Damage is common after hitting road debris, deep snow, or obstacles during off-road driving.
  • Sagging or Misalignment: A guard that is hanging down or not sitting flush with the bodywork is a clear sign of broken mounting points. This reduces its effectiveness and increases the risk of it being completely torn off while driving.

Warning: A Reddit user reported that catching the small factory-installed front aerodynamic piece (often mistaken for a mud flap) on a snowbank ripped off part of the wheel well liner. Even minor impacts to these lower plastic parts can cause collateral damage to adjacent panels.

Known Issues, TSBs, and Recalls

As of mid-2024, there are no official recalls or Technical Service Bulletins (TSBs) from Rivian or the NHTSA related to the mud guards, splash shields, or wheel well liners on the 2022-2024 Rivian R1S.

Buying a Used Mud Guard or Splash Shield

Purchasing a used OEM splash shield or a set of used aftermarket mud flaps can be a cost-effective option. Because these are simple plastic parts, a visual inspection is usually sufficient to determine their condition.

What to Inspect on a Used Part:

  • Check All Mounting Points: This is the most critical area. Inspect every hole where a screw or clip would attach. Look for cracks radiating from the holes or elongated holes, which indicate the part was loose or stressed. A guard with a broken mounting point will not install securely.
  • Look for Cracks and Warping: Examine the entire surface for cracks, especially on the factory underbody shields which can be brittle. Lay the part on a flat surface to check for any significant warping that might prevent a flush fit.
  • Assess Material Flexibility (for Mud Flaps): If buying aftermarket mud flaps, bend them slightly to ensure the material isn't brittle from UV exposure. High-quality materials like polyurethane should remain flexible.
  • Verify Hardware Inclusion: For aftermarket mud flap kits, ensure all proprietary brackets, screws, and clips are included. While many kits use factory hardware, some require specific brackets that can be difficult to source separately.

Why Choose Used OEM or Quality Aftermarket?

For the underbody shields, a used OEM part (like PT00048748) is the best choice as it guarantees a perfect fit with the factory mounting locations. For accessory mud flaps, a used set from a reputable brand like Rally Armor or EV Sportline is often superior to a new, cheap, no-name alternative. The quality of the plastic or polyurethane in premium brands resists cracking in cold weather and fading from sun exposure, ensuring better durability and appearance over time.

Replacement and Installation

Replacing a factory underbody shield or installing an aftermarket mud flap kit is a straightforward DIY task.

  • Difficulty: 1 out of 5
  • Estimated Time: 0.5 - 1 hour for a set of four mud flaps.
  • Tools Required: Basic hand tools, typically a Torx driver set (T20, T25 are common), and possibly a trim removal tool to safely pop out any plastic clips.

The general process for installing aftermarket mud flaps involves removing existing factory screws from the wheel well liner, positioning the new mud flap, and reinstalling the screws through the flap. No drilling is required for most quality kits designed for the R1S.

Pro Tip: Before installation, thoroughly clean the wheel well area where the mud flap will sit. This ensures a flush fit and prevents dirt from being trapped against the paint.

Cost Comparison

The cost can vary significantly depending on whether you are replacing a single factory shield or adding a full set of aftermarket flaps.

Part Type Estimated Cost
New OEM Underbody Shield (Single, e.g., PT00048748) $95 - $120
New Aftermarket Mud Flap Kit (Set of 4) $45 - $250+
Used OEM Underbody Shield (Single) $40 - $75
Shop Labor for Installation $70 - $200

Frequently Asked Questions (FAQ)

Do I really need to add mud flaps to my R1S?

While not required, they are highly recommended if you frequently drive on gravel, dirt roads, or in wet/snowy climates. They provide significant protection against paint chipping on the lower doors and rocker panels, which can be expensive to repair.

Are the front and rear mud flaps the same part?

No. For all aftermarket kits, the front and rear mud flaps are shaped differently to match the contours of the front and rear wheel wells. They are not interchangeable.

Will installing mud flaps reduce my R1S's driving range?

Any modification that affects aerodynamics can theoretically impact range. However, the effect of well-designed, slim-profile mud flaps is generally considered to be negligible and not noticeable in real-world driving.

Can I replace just one damaged underbody splash shield?

Yes. The factory underbody shields are individual parts. For example, the part number PT00048748 is specifically for the right rear underbody battery splash guard. You can purchase and replace only the specific panel that is damaged.

Technical Specifications

OEM Part Numbers: PT00048748 (Right Rear Underbody Battery Splash Guard)

Material: Typically ABS plastic or Polypropylene for factory shields; Polyurethane or flexible ABS for aftermarket flaps.

Wrenchy
Article researched & written by
Go-Parts' AI research assistant. Every article is backed by live web research, verified OEM data, and real technician knowledge — so you get accurate, up-to-date information you can trust.
Meet Wrenchy → Updated Jul 21, 2026

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.

Year Coverage
This article covers the Mud Guard for:
  • Rivian R1S: 202220232024
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