The 2021 Audi S4 has 25 steering parts with verified fitment on this page — 3 part types and 7 brands, covering both the 3.0L V6 Supercharged and the 3.0L V6 Turbocharged. Each part includes a manufacturer part number and application notes.
On the 2021 Audi S4, the steering system connects driver to road through the rack, pump, tie rods, and column components. All 25 listed parts are Tie Rod End (20 parts), Knuckle (3 parts) and Rack and Pinion Bellow (2 parts).
The 2021 Audi S4 was sold with both the 3.0L V6 Supercharged and the 3.0L V6 Turbocharged. 20 parts fit every engine; the other 5 are engine-specific. Each part shows which engine(s) it fits.
7 brands supply steering parts for the 2021 Audi S4, led by MEVOTECH (6 parts), VAICO (4 parts) and BECK/ARNLEY (4 parts), plus 4 more brands. Quality grades include Daily Driver and Economy.
A "Popular" badge means the source catalog flagged the part as frequently chosen for the 2021 Audi S4. 4 parts have it, including MEVOTECH MS70717 (Tie Rod End) and MEVOTECH MS70641 (Tie Rod End). Each part number opens a page with every vehicle that part fits.
Knuckle
Daily Driver
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VAICO Fits: all 2021 S4 engines | V107797 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front Right | View on Amazon |
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VAICO Fits: all 2021 S4 engines | V107796 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front Left | View on Amazon |
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VAICO Fits: all 2021 S4 engines | V107826 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Description: Front Axle Left | View on Amazon |
This table covers the steering knuckles that carry the hub, caliper and ball joints.
VAICO supplies the 3 Knuckle parts for the 2021 Audi S4. All of them fit every engine offered in the 2021 S4.
The Daily Driver section lists 1 option from VAICO — grouped for everyday commuting duty. VAICO V107797 is listed in this group.
In the Economy grade, VAICO supplies 1 part: the catalog's value-priced group. A representative part number is VAICO V107796.
1 ungrouped part is not assigned to a grade, with the same engine-level match.
Listed part numbers: VAICO V107797, VAICO V107796 and VAICO V107826.
Rack and Pinion Bellow
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| BECK/ARNLEY Fits: all 2021 S4 engines | 1033085 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| DELPHI Fits: 3.0L V6 Turbocharged | TBR4541 | 🇺🇸 US 🇨🇦 CA | View on Amazon |
This table covers the rubber boots that seal the inner tie-rod joints on the rack.
2 Rack and Pinion Bellow parts for the 2021 Audi S4 come from 2 brands — BECK/ARNLEY and DELPHI. 1 part fits every engine; the other 1 is engine-specific.
Part numbers include BECK/ARNLEY 1033085 and DELPHI TBR4541.
Tie Rod End
Daily Driver
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| MEVOTECH Popular Fits: all 2021 S4 engines | MS70717 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | SupremeIncludes Hardware | View on Amazon |
| MEVOTECH Popular Fits: all 2021 S4 engines | MS70641 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | SupremeIncludes Jam Nut | View on Amazon |
| MEVOTECH Popular Fits: all 2021 S4 engines | MS70642 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | SupremeIncludes Jam Nut | View on Amazon |
| SUSPENSIA Popular Fits: all 2021 S4 engines | X01TE7443 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front Right Outer | View on Amazon |
| DELPHI Fits: 3.0L V6 Turbocharged | TA3299 | 🇺🇸 US 🇨🇦 CA | Inner | View on Amazon |
| DELPHI Fits: 3.0L V6 Turbocharged | TA3302 | 🇺🇸 US 🇨🇦 CA | Left Outer | View on Amazon |
| DELPHI Fits: 3.0L V6 Turbocharged | TA3303 | 🇺🇸 US 🇨🇦 CA | Right Outer | View on Amazon |
| MOOG Fits: all 2021 S4 engines | ES801458 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front Left Outer | View on Amazon |
| MOOG Fits: all 2021 S4 engines | ES801459 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front Right Outer | View on Amazon |
| MOOG Fits: all 2021 S4 engines | EV801758 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front Inner | View on Amazon |
| SUSPENSIA Fits: all 2021 S4 engines | X01TR7246 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front Inner | View on Amazon |
| SUSPENSIA Fits: all 2021 S4 engines | X01TE7444 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front Left Outer | View on Amazon |
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| BECK/ARNLEY Fits: all 2021 S4 engines | 1018349 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front Inner | View on Amazon |
| BECK/ARNLEY Fits: all 2021 S4 engines | 1018487 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front Left Outer | View on Amazon |
| BECK/ARNLEY Fits: all 2021 S4 engines | 1018488 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front Right Outer | View on Amazon |
| DORMAN Fits: all 2021 S4 engines | 543284 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front Inner | View on Amazon |
| MEVOTECH Fits: all 2021 S4 engines | GS70717 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Original Grade | View on Amazon |
| MEVOTECH Fits: all 2021 S4 engines | GS70641 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Original Grade | View on Amazon |
| MEVOTECH Fits: all 2021 S4 engines | GS70642 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Original Grade | View on Amazon |
| VAICO Fits: 3.0L V6 Turbocharged | V105273 | 🇺🇸 US | InnerGrade: AM | View on Amazon |
This table covers the inner and outer tie-rod ends that steer each front knuckle. Typical signs include play on center, a feathered front tire, or a boot that has split and packed with grit. Replace inner and outer ends together on a high-mileage axle, then get an alignment.
20 Tie Rod End parts for the 2021 Audi S4 come from 7 brands — MEVOTECH, SUSPENSIA, DELPHI and 4 other brands. The "Popular" part is MEVOTECH MS70717. 16 parts fit every engine; the other 4 are engine-specific.
Daily Driver: 12 parts, from MEVOTECH, SUSPENSIA, DELPHI and 1 other brand. A representative part number is MEVOTECH MS70717.
The Economy section: 8 options from BECK/ARNLEY, MEVOTECH, DORMAN and 1 other brand. BECK/ARNLEY 1018349 is listed in this group.
Buying Steering Parts for a 2021 Audi S4
On this vehicle, the steering system connects driver to road through the rack, pump, tie rods, and column components.
- Match the engine first. Some steering parts fit every engine; others are engine-specific. Each row shows which engine(s) it fits.
- Read the notes on each row for position, trim and spec qualifiers before you order.
- Where labor overlaps, replace the inner and outer tie-rod ends together on higher-mileage vehicles, then get an alignment.
- Cross-reference the manufacturer part number against your old part or a service-manual listing.
Start with the largest groups on this page: Tie Rod End and Knuckle .
Frequently Asked Questions
How many steering parts fit the 2021 Audi S4?
Our catalog currently lists 25 steering parts for the 2021 Audi S4 across 3 subcategories and 7 brands, covering both the 3.0L V6 Supercharged and the 3.0L V6 Turbocharged. Each part is matched to the engine(s) it fits.
Do steering parts differ between 2021 Audi S4 engines?
Some do. 20 parts fit every engine; the other 5 are engine-specific. Each row (and the filter at the top) shows which. If you're unsure which engine you have, check the emissions label under the hood or the 8th character of your VIN.
What are the signs of steering problems on a 2021 Audi S4?
Common symptoms include play or looseness on center, a whine when turning, fluid weeping from rack boots, or uneven tire wear on the front axle. If you notice any of these, identify the affected subcategory above and cross-reference the part numbers listed.
What should I replace at the same time?
Where labor overlaps, replace the inner and outer tie-rod ends together on higher-mileage vehicles, then get an alignment.
What do the market flags (US, CA, MX) on each part mean?
They show the market for which the manufacturer published application data for that part — where the vehicle was first sold, not where the part was made. If your 2021 Audi S4 was originally sold in the US, the safest choice is a part marked for the US market.
How do I make sure a part fits my 2021 Audi S4?
First match the engine — each row shows which engine(s) the part fits. Then flush old power-steering fluid when replacing a pump or rack — grit in the old fluid is the number-one cause of repeat failure. The notes column carries position and trim qualifiers where they apply.
Other Parts for the 2021 Audi S4
Steering Parts for Other Audi S4 Years
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Manufacturer names, model designations and part numbers are used for identification and fitment reference only. AutoFactsDB is an independent catalog and is not affiliated with, endorsed by, or sponsored by any vehicle manufacturer displayed on this page.