Delphi TBR4578 Rack and Pinion Bellows - Front

OE-style steering bellows protection

Delphi TBR4578 is a rack and pinion bellows built for front steering applications where the boot must keep contaminants away from the steering gear. It is engineered with OE-focused dimensional and material analysis to match the original part more closely.

Compatible with Porsche Taycan, Porsche Panamera, Audi e-tron GT, Audi RS e-tron GT, and multiple Mercedes-Benz applications, this bellows supports clean steering gear operation in demanding conditions. Delphi TBR4578 is a practical replacement for drivers and technicians looking for a direct-fit steering boot solution.

• Rack and pinion bellows for steering gear protection
• Front application coverage where listed in fitment
• OE-focused dimensional and material analysis for closer matching
• Tested for temperature extremes below -40 C and above 120 C
• Exposed to 720 hours of salt spray testing

Fitment details

Fits 2020-2024 Porsche Taycan, front.

Fits 2017-2023 Porsche Panamera, front.

Fits 2022-2023 Audi e-tron GT, front.

Fits 2022-2023 Audi RS e-tron GT, front.

Fits 2021 Mercedes-Benz AMG GT 43, front.

Fits 2019-2021 Mercedes-Benz AMG GT 53, front.

Fits 2019-2021 Mercedes-Benz AMG GT 63, front.

Fits 2015-2021 Mercedes-Benz C300, front.

Fits 2020-2021 Mercedes-Benz C43 AMG, front.

Fits 2020-2021 Mercedes-Benz CLS450, front.

Fits 2019-2021 Mercedes-Benz CLS53 AMG, front.

Fits 2020-2021 Mercedes-Benz E350, front.

Fits 2019-2021 Mercedes-Benz E450, front.

Fits 2019-2021 Mercedes-Benz E53 AMG, front.

Fits 2016-2021 Mercedes-Benz GLC300, front.

Fits 2017-2021 Mercedes-Benz GLC43 AMG, front.

Fits 2018-2021 Mercedes-Benz GLC63 AMG, front.

Fits 2018-2021 Mercedes-Benz GLC63 AMG S, front.

Fits 2021 Mercedes-Benz Maybach S580, front.

Fits 2016-2021 Mercedes-Benz Metris, front.

Fits 2021 Mercedes-Benz S500, front.

Fits 2021 Mercedes-Benz S580, front.

Fits 2018-2020 Mercedes-Benz GLC350e, front.

Fits 2017-2019 Mercedes-Benz E300, front.

Fits 2017-2018 Mercedes-Benz E43 AMG, front.

Fits 2018 Mercedes-Benz E63 AMG S, front.

Fits 2016 Mercedes-Benz C450 AMG, front.

Common replacement uses

• Replacing a torn or cracked steering bellows
• Keeping dirt and moisture away from the rack and pinion assembly
• Addressing steering gear contamination after boot failure
• Restoring protective coverage around the steering rack

Installation notes and quality

Confirm the front application and vehicle-specific fitment before installation. Delphi applies OE expertise to its aftermarket steering portfolio and subjects parts to extreme temperature cycling and salt spray exposure to verify durability. Part number TBR4578 is also referenced by Beck/Arnley 103-3181 for the same application.