33 Drivetrain parts are listed for the 2021 Audi S4, in 7 part types, covering both the 3.0L V6 Supercharged and the 3.0L V6 Turbocharged. Each one has a brand, a manufacturer part number and notes that say where it fits.
The drivetrain system on the 2021 Audi S4 moves power from transmission to wheels through axles, CV joints, driveshafts, differentials and wheel-end hardware. The largest groups are Gear Oil (8 parts), Transfer Case Fluid (7 parts) and CV Axle (6 parts). The other 4 part types cover the remaining 12 parts.
The 2021 Audi S4 was sold with both the 3.0L V6 Supercharged and the 3.0L V6 Turbocharged. 31 parts fit every engine; the other 2 are engine-specific. Each part shows which engine(s) it fits.
The most listed brands for 2021 Audi S4 drivetrain parts are VALVOLINE (12 parts), VAICO (6 parts) and GKN (5 parts), plus 6 more brands. Quality grades include Standard Replacement and Premium.
6 parts on this 2021 Audi S4 page carry a "Popular" badge — the source catalog's flag for options frequently chosen for this vehicle — including TOP NOTCH TN19007PR (CV Axle) and BECK/ARNLEY 1033141 (CV Joint Boot). Click any part number to see every vehicle that part fits.
Axle Shaft Seal
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| TIMKEN Fits: all 2021 S4 engines | SL260517 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | RearExcept Active Differential | View on Amazon |
This table covers the seals where an axle shaft exits the housing. Typical signs include a wet housing, a drip after sitting, or fluid flung off a rotating shaft. Fix the surface the seal rides on. A new seal on a grooved shaft will leak again.
This group shows a single part: TIMKEN SL260517.
CV Axle
Premium
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| TOP NOTCH Popular Fits: all 2021 S4 engines | TN19007PR | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Performance | View on Amazon |
| GSP Fits: all 2021 S4 engines | PR23011 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Performance Revolution | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| APWI Fits: all 2021 S4 engines | AD8352 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front | View on Amazon |
| GSP Fits: all 2021 S4 engines | NCV23011 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front | View on Amazon |
| TOP NOTCH Fits: all 2021 S4 engines | TN19007 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front | View on Amazon |
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GKN Fits: all 2021 S4 engines | GKND12939 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Outboard Joint Type: Fix Ball Joint SX | View on Amazon |
This table covers the complete CV axle shafts from differential (or hub) to wheel. Typical signs include a click in tight turns, grease flung around the wheel well, or a vibration that builds with speed. A torn boot caught early is a boot kit; caught late it is the whole axle. Torque the axle nut to the method in the notes.
6 CV Axle parts for the 2021 Audi S4 come from 4 brands — TOP NOTCH, GSP, APWI and 1 other brand. The "Popular" part is TOP NOTCH TN19007PR. Every part fits both the 3.0L V6 Supercharged and the 3.0L V6 Turbocharged.
In the Premium grade, TOP NOTCH and GSP supply 2 parts: a step above OE specification in materials, tolerances or warranty terms. A representative part number is TOP NOTCH TN19007PR.
In the Standard Replacement grade, APWI, GSP and TOP NOTCH supply 3 parts: built to original-equipment specification. A representative part number is APWI AD8352.
1 further part sits outside the graded sections, with the same engine-level match.
This group includes TOP NOTCH TN19007PR, GSP PR23011 and APWI AD8352 and the remaining parts above.
CV Joint
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GKN Fits: all 2021 S4 engines | 306277 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Pre-lubricatedThermosplastic Elastomer (TPE) | View on Amazon |
| VAICO Fits: 3.0L V6 Turbocharged | V107738 | 🇺🇸 US | Front Inner | View on Amazon |
This table covers the constant-velocity joints at each end of a drive axle.
2 CV Joint parts for the 2021 Audi S4 come from 2 brands — GKN and VAICO. 1 part fits every engine; the other 1 is engine-specific.
This group includes GKN 306277 and VAICO V107738.
CV Joint Boot
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| BECK/ARNLEY Popular Fits: all 2021 S4 engines | 1033141 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front Outer | View on Amazon |
| GKN Fits: all 2021 S4 engines | 306313 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | OUTER Diameter 1.023 InThermoplastic Elastomer | View on Amazon |
| GKN Fits: all 2021 S4 engines | 306188 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | OUTER Diameter 1.063 InThermoplastic Elastomer | View on Amazon |
| REIN Fits: all 2021 S4 engines | BKN0109 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front Outer | View on Amazon |
| VAICO Fits: 3.0L V6 Turbocharged | V105635 | 🇺🇸 US | Front OuterGrade: AM | View on Amazon |
This table covers the boots that keep grease in a CV joint. Typical signs include a split boot, grease flung around the joint, or a click once grit is inside. A boot caught early is a kit. Once the joint has clicked, the joint itself is usually worn.
5 CV Joint Boot parts for the 2021 Audi S4 come from 4 brands — GKN, BECK/ARNLEY, REIN and 1 other brand. The "Popular" part is BECK/ARNLEY 1033141. 4 parts fit every engine; the other 1 is engine-specific.
Listed part numbers: BECK/ARNLEY 1033141, GKN 306313 and GKN 306188, plus the other parts above.
Drive Shaft
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GKN Fits: all 2021 S4 engines | GKNP20093 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| GSP Fits: all 2021 S4 engines | PS901720 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Rear | View on Amazon |
| TOP NOTCH Fits: all 2021 S4 engines | TN2338PS | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Rear | View on Amazon |
| VAICO Fits: all 2021 S4 engines | V107729 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Length: 463From 01/25/2016 | View on Amazon |
This table covers the driveshafts that carry torque from the transmission or transfer case.
4 Drive Shaft parts are listed for the 2021 Audi S4, from GKN, GSP, TOP NOTCH and 1 other brand. All of them fit every engine offered in the 2021 S4.
This group includes GKN GKNP20093, GSP PS901720 and TOP NOTCH TN2338PS and the remaining parts above.
Gear Oil
SAE 75W-140
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VALVOLINE Popular Fits: all 2021 S4 engines | VV982 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Advanced Full Synthetic SAE 75W-14 0 Gear Oil1 Quart | View on Amazon |
| VALVOLINE Fits: all 2021 S4 engines | 889787 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Full Synthetic SAE 75W-14 0 Gear Oil1 Quart Flex Fill | View on Amazon |
| VALVOLINE Fits: all 2021 S4 engines | 887344 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Advanced Full Synthetic SAE 75W-14 0 Gear Oil1 Gallon | View on Amazon |
| VALVOLINE Fits: all 2021 S4 engines | VV981 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Advanced Full Synthetic SAE 75W-14 0 Gear Oil5 Gallon | View on Amazon |
SAE 75W-90
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VALVOLINE Popular Fits: all 2021 S4 engines | VV975 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Advanced Full Synthetic SAE 75W-90 Gear Oil1 Quart | View on Amazon |
| VALVOLINE Fits: all 2021 S4 engines | 889785 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Full Synthetic SAE 75W-90 Gear Oil1 Quart Flex Fill | View on Amazon |
| VALVOLINE Fits: all 2021 S4 engines | 882505 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Advanced Full Synthetic SAE 75W-90 Gear Oil1 Gallon | View on Amazon |
| VALVOLINE Fits: all 2021 S4 engines | 723856 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Advanced Full Synthetic SAE 75W-90 Gear Oil5 Gallon | View on Amazon |
This table covers the gear oils specified for the axle or transfer case. Typical signs include a low-oil lamp, knocking, or oil that has gone thin before the next interval. Match the viscosity and spec in the notes, not just the weight on the bottle.
8 Gear Oil parts for the 2021 Audi S4 come from VALVOLINE. The "Popular" part is VALVOLINE VV982. Every part fits both the 3.0L V6 Supercharged and the 3.0L V6 Turbocharged.
The SAE 75W-140 section lists 4 options from VALVOLINE — grouped under the catalog's "SAE 75W-140" designation — the notes column spells out what sets them apart. VALVOLINE VV982 is listed in this group.
The SAE 75W-90 section lists 4 options from VALVOLINE — grouped under the catalog's "SAE 75W-90" designation — the notes column spells out what sets them apart. VALVOLINE VV975 is listed in this group.
This group includes VALVOLINE VV982, VALVOLINE 889787 and VALVOLINE 887344 and the remaining parts above.
Transfer Case Fluid
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VALVOLINE Popular Fits: all 2021 S4 engines | VV975 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Advanced Full Synthetic SAE 75W-90 Gear Oil1 Quart | View on Amazon |
| VALVOLINE Popular Fits: all 2021 S4 engines | 889785 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Full Synthetic SAE 75W-90 Gear Oil1 Quart Flex Fill | View on Amazon |
| VAICO Fits: all 2021 S4 engines | V600430 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Transfer Case Oil DTF-1 L | View on Amazon |
| VAICO Fits: all 2021 S4 engines | V600431 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Grade: AMTransfer Case Fluid, DTF-1 - 5 Liter | View on Amazon |
| VAICO Fits: all 2021 S4 engines | V600432 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Grade: OEMTransfer Case Oil DTF-1-20 L | View on Amazon |
| VALVOLINE Fits: all 2021 S4 engines | 882505 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Advanced Full Synthetic SAE 75W-90 Gear Oil1 Gallon | View on Amazon |
| VALVOLINE Fits: all 2021 S4 engines | 723856 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Advanced Full Synthetic SAE 75W-90 Gear Oil5 Gallon | View on Amazon |
This table covers the fluids specified for the transfer case. Typical signs include discolored fluid, a burnt smell, or a level that keeps dropping. Use only the specification in the notes — the tables group grades because they are not interchangeable.
7 Transfer Case Fluid parts for the 2021 Audi S4 come from 2 brands — VALVOLINE and VAICO. The "Popular" part is VALVOLINE VV975. Every part fits both the 3.0L V6 Supercharged and the 3.0L V6 Turbocharged.
This group includes VALVOLINE VV975, VALVOLINE 889785 and VAICO V600430 and the remaining parts above.
Buying Drivetrain Parts for a 2021 Audi S4
On this vehicle, the drivetrain system moves power from transmission to wheels through axles, CV joints, driveshafts, differentials and wheel-end hardware.
- Match the engine first. Some drivetrain 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 differential or transfer-case fluid with any axle or seal job while everything is already open.
- Cross-reference the manufacturer part number against your old part or a service-manual listing.
Start with the largest groups on this page: Gear Oil and Transfer Case Fluid .
Frequently Asked Questions
How many drivetrain parts fit the 2021 Audi S4?
Our catalog currently lists 33 drivetrain parts for the 2021 Audi S4 across 7 subcategories and 9 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 drivetrain parts differ between 2021 Audi S4 engines?
Some do. 31 parts fit every engine; the other 2 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 drivetrain problems on a 2021 Audi S4?
Common symptoms include clicking in tight turns, a clunk when shifting between drive and reverse, vibration that builds with speed, or gear oil on the inside of a wheel. 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 differential or transfer-case fluid with any axle or seal job while everything is already open.
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 a torn CV boot caught early is a cheap boot kit; caught late it is a whole axle — inspect before deciding which to buy. The notes column carries position and trim qualifiers where they apply.
Other Parts for the 2021 Audi S4
Drivetrain Parts for Other Audi S4 Years
Switch vehicle or jump to a subcategory
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.