This article will provide the necessary steps and information on how to change the Audi A4 Quattro rear differential fluid in the B8 chassis. We will also discuss what the rear differential fluid change interval is and why changing the rear diff fluid is important. Although this is demonstrated on a 2012 Audi A4 Quattro rear differential, the procedures also apply to the following Audi models without sport rear differentials.
- 2009-2016 Audi A4 Quattro (B8 Chassis, 1.1 Liter Capacity)
- 2013-2016 Audi A4 Allroad (1.1 Liter Capacity)
- 2008-2017 Audi A5 Quattro (1.1 Liter Capacity)
- 2005-2011 Audi A6 Quattro (0.9-1.5 Liter Capacity)
- 2012-2018 Audi A6 Quattro (0.9 Liter Capacity)
- 2012-2018 Audi A7 (0.9 Liter Capacity)
- 2011-2018 Audi A8 Without Torque Vectoring Sport Rear Differential (0.9 Liter Capacity)
- 2010-2017 Audi Q5 (1 Liter Capacity)
- 2010-2016 Audi S4 Without Torque Vectoring Sport Rear Differential (1.1 Liter Capacity)
- 2008-2017 Audi S5 Without Torque Vectoring Sport Rear Differential (1.1 Liter Capacity)
- 2007-2011 Audi S6 (0.9 Liter Capacity)
- 2012-2018 Audi S6 Without Torque Vectoring Sport Rear Differential (0.9 Liter Capacity)
- 2012-2018 Audi S7 Without Torque Vectoring Sport Rear Differential (0.9 Liter Capacity)
- 2007-2009 Audi S8 (1.5 Liter Capacity)
- 2013-2018 Audi S8 Without Torque Vectoring Sport Rear Differential (0.9 Liter Capacity)
- 2014-2017 Audi SQ5 Without Torque Vectoring Sport Rear Differential (1 Liter Capacity)
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Audi A4 Rear Differential Fluid Change Interval
When should you change your Audi A4 rear differential fluid? We recommend changing the fluid around 80-90,000 miles. However, this can change depending on your driving style. If the vehicle sees spirited driving, you can service the rear differential fluid as early as 50-70,000 miles. Vehicles used for racing events or autocross should have the differential fluid changed every 24-48 hours when exposed to real racetrack conditions. Abiding by these recommended differential fluid change intervals can eliminate and minimize rear differential issues.
Why Should Audi A4 Rear Differential Fluid Be Changed?
Your differential has a good amount of moving internal components. This includes bearings, pinion gears, and crown gears. These internal components rely solely on the diff fluids lubrication film strength for protection and longevity. Through use, the diff fluid experiences excessive shear loads and various heat cycles. In time these heat cycles and excessive loads deplete the lubricating properties and film strength of the differential fluid. Continued use of old differential fluid will result in differential bearing, pinion gear wear, and failure. Therefore, having regular differential fluid changes is important. Changing the rear differential fluid as routine maintenance will greatly extend the life of the rear differential, minimize driveline noises due to wear, and ensure the bearings and gears receive reliable clean lubrication.
How to Confirm You Have a Standard Quattro Differential
This information applies to customers using this how-to article for changing the rear differential fluid in a 2010 and newer Audi A8, S4 and S5, S6, S7, S8, and SQ5 models. If your car does have a sport rear differential these instructional guidelines will not apply to your rear differential fluid change. When referencing the sport differential this is referring to the torque vectoring differential. From our understanding, all Audi A4, A5, A6, A7, and Q5 models came equipped with a standard rear differential and not the sport differential. The sport rear differential was optioned in the A8, S4, S5, S6, S7, S8, and SQ5 models. Typically, the sport diff was in the Prestige and Sport trim packaged models. Also, from our knowledge, all Audi RS5 and RS7 models came with the sport differential.
To confirm which type of rear differential you have a visual inspection of the rear differential is needed. The sport rear differential has an electronic servo motor unit with several sensors located on the back side of the diff. The standard rear differential will not have an electronic servo motor unit or sensors located on the rear side of the differential. Please confirm your rear differential type before proceeding.
The sport rear differentials have 3 different fluid chambers and 2 different fluids for them. This requires a more in-depth fluid change procedure different from this one.
Audi A4 Rear Differential Fluid Change Parts Needed
- 2 liters of RAVENOL VSG Gear Oil (SKU Part Number J1C1109)
- Thread Sealant Compound (Optional - A quality thread sealant compound can minimize a possible weeping differential drain plug and is great for added security in knowing it won’t leak. SKU Part Number U1S1000)
The factory rear differential fluid capacity is 1.1 liters. Some individuals have tried to save money by only using 1 liter. Our recommendation is to always use the exact amount of fluid the factory recommends. This will ensure all the pinion bearings and gears in the rear differential receive the proper lubrication and oil submersion. RAVENOL VSG is equivalent and compatible with Audi rear differential fluid part numbers G 052 145 A1 (500 ml), G 052 145 A2 (1 Liter), or G 052 145 S2 (1 Liter).
Audi A4 Rear Differential Fluid Change Tools Needed
- 3/8 or 1/2 Inch Drive 10mm Hex Bit Socket (6 point)
- 3/8 or 1/2 Inch Racket (dependent on bit socket)
- Oil Drain Pan Container
- Fluid Pump Tool (Optional - It is always easier with a pump and a flexible hose. Keep in mind the RAVENOL bottles have a built-in flex hose in the cap and can work for most applications. Possible fluid pump solutions are SKU Part Numbers J91001 or T2A0129.)
Disclaimer: Blauparts recommends having an A.S.E. certified Audi mechanic perform vehicle maintenance. Always refer to your vehicle owner's manual and factory manual for rear differential fluid change instructions. Always wear safety gloves and wear safety glasses when performing rear differential gear oil changes.
Important Note: It’s important to note that some early 2011 and older models could have rear differentials with slightly different drain plug and fill plug locations. The drain plug is still located on the bottom side of the differential. The fill plug can be located just behind the rear of the axle or on the driver side of the differential. These differentials can be identified as different typically because they are painted black from the factory. Even though the differentials have some slight differences the fluid draining and filling procedures and sequences are the same.
Step-By-Step How to Instructions
How To Step 1
Since the rear differential fluid gear oil is thicker it is best to get the rear differential fluid warm before draining it. This can be done by taking your car for a quick 10-15 minute drive. This will allow the rear differential and the viscosity of the fluid to get thinner and flow more easily from the rear differential when drained.
How To Step 2
Lift the vehicle on an automotive lift of jack stands so that the vehicle is in a perfectly level position. To confirm you are lifting the vehicle correctly reference your factory owner’s manual for the proper vehicle lift point locations and procedures. The vehicle needs to be in a level position to confirm the correct differential fluid level when refilling. If the vehicle is not level this can cause the rear differential fluid level to be incorrect and could damage the rear differential.
How To Step 3
Locate, loosen (Counterclockwise), and remove the 10mm hex bit rear differential fluid fill plug. This is located on the right passenger side of the rear differential. It is always best to confirm the fill plug can be removed before draining the differential fluid. This will confirm you will have a way to refill the differential with fluid in case the fill plug is seized or can’t be removed. (Images 1, 2, and 3)
How To Step 4
Locate the 10mm hex bit rear differential fluid drain plug on the bottom center area of the differential. Loosen, and remove the rear differential fluid drain plug and allow the old dirty rear differential fluid to thoroughly drain into a drain pan container. (Images 4, 5, and 6)
How To Step 5
Once the old fluid has been drained use a clean rag to clean the drain plug and excess gear oil from around the drain plug area on the differential. Note that the drain and fill plugs do not have a washer or seal. It's best to clean and ensure all mating threads and surfaces of the drain plug and differential are clean. This can help minimize any possibility of leaks. If you are choosing to use a thread compound sealant on the drain plug it can be installed at this time. Lightly apply a small amount of sealant to a dry free from oil drain plug. Apply a light and even amount of thread compound sealant to the threaded area only. It’s not necessary to gunk the drain plug up with excessive amounts of thread compound sealer. Re-install the rear differential drain plug. Using a Torque wrench torque the drain plug to 30 ft-lb. (Image 7)
How To Step 6
Using the J1C1109 rear differential fluid, begin filling the rear differential through the fill port on the right driver side of the differential. Fill the differential with fluid until you see the differential fluid flow from the fill port. Make sure you have your drain pan container handy to catch the flow of fluid. Once you see the fluid flow in a heavy stream from the fill port the rear differential fluid level is correct. This step should always be done with the vehicle and differential in a 100% level condition to confirm the proper fluid level. This step should never be done with the vehicle not level.
Once the fluid level has been confirmed I like to wait 10 minutes or so to allow any air pockets to leave the rear differential. We also like to rotate the rear axles and driveshaft several times. Many times, this will allow 1 or 2 more pumps (a small amount) of rear differential fluid to still be added. The fluid capacity for the rear differential is 1.1 liters. This is a general fluid level and it's always better to base the differentials fluid level off the fluid overflowing from the side fill plug port. (Image 8 and 9)
How To Step 7
Once the fluid level has been confirmed you can re-install the rear differential fluid fill plug and torque it to 30 ft-lb. (Image 10)
How To Step 8
Use a rag to remove all excess differential fluid from the differential. The differential should be completely cleaned of all fluid. This will later help you to inspect and confirm the differential does not have any leaks.
How To Step 9
Once you have the vehicle on the ground you can take the car for a simple 5-10 minute test drive. After the test drive. Look at the differential and confirm you do not have any leaks coming from the differential drain plug.
How to Step 10
Dispose of your old rear differential fluid responsibly by taking it to a certified recycling collection center.
Tech Tip: It’s also good to note in your vehicle service records the vehicle mileage at the time of the rear differential fluid change, as well as, when you might want to change it next. Keeping detailed service records is a must for proper vehicle maintenance and improving the future resale value of your car.