Audi was one of the first who began to complete the cars produced with a CVT gearbox. Over time, car owners have gained some experience in operating such vehicles. To date, repair or replacement of the Audi A4 CVT is not something complicated, this kind of operation is performed by many service centers. We will talk about the features of this procedure in our article.
Design features of Audi Variators
Structurally, the Audi variator contains the following elements:
- Two “wet” multi-plate clutches that separate the engine and gearbox. Clutches are friction clutches forward and reverse. Structurally, they are similar to conventional devices that are installed on cars with automatic transmission.
- Planetary gear used during reverse gear. The system by which the box is controlled limits the speed of reversing.
- CVT transmission, which smoothly changes the gear moment. It consists of driven and driven pulleys interconnected. Each of the pulleys consists of two conical shafts. The driving element is connected to the engine crankshaft through an intermediate gear. The driven shaft transmits torque to the final drive. During operation of the box, one of the shafts on the pulley is movable, which allows the control system to change its diameter.
- The metal chain that was first used by Audi. The chain made it possible to increase the number of gear ratios by reducing the surface on which the chain comes into contact with the shaft. The noise reduction during the operation of the circuit was facilitated by the use of different sized links in it.
- Clamping and adjusting hydraulic cylinders mounted on each of the shafts. Using the first, the chain is pressed against the gross discs. To provide the necessary clamping force, a torque sensor is used that is attached to the drive shaft. Due to the second, the gear ratio is regulated, i.e., the diameter of the shaft changes.
- Differential and final drive.
- A control system that ensures the correct operation of the transmission. The system consists of input controllers, a control unit and a hydraulic mechanism playing the role of an executive device. Using the control device, the optimal gear ratio is selected, depending on the driving conditions and the desire of the driver.
- An oil pump that circulates oil in a box.
- Ejection pump, cooling the clutches. The principle of its functioning is based on the supply of transmission fluid due to its discharge. The oil is cooled in a heat exchanger, which is part of the engine cooling system.
- Concern engineers argue that the best dynamism during the ride is achieved through the use of variators “Multitronic”. A normally functioning transmission also saves fuel.
Before buying an Audi A4 with a CVT gearbox, motorists ask themselves a question regarding its service life. The resource of the checkpoint depends on the operating conditions and the frequency of servicing the car. In some cases, problems requiring the replacement of the Audi A4 variator begin after 40 thousand kilometers, in others – the car passes 200 thousand km. The sensitivity of the box to operating conditions affects the attitude of owners to such cars.
Repair and replacement of the Audi A4 CVT is best done by an authorized dealer or service station. “Officials” should be contacted if the car is under warranty, since the cost of work is higher.
CVTs on Audi A4 cars
Audi A4 applies to mid-range vehicles with a longitudinally-mounted powertrain. A potential buyer can choose front-wheel drive or four-wheel drive. For the first time, cars were presented to the public in 1994, a series of updates were later made. They began to complete the new model with the Multitronic variator.
1. 01J / Multitronic VL-300.
In the period 1999-2007 the cars were equipped with variable-speed gearboxes Audi 01J or Multitronic VL-300.
Installed on the model of a car with a longitudinal engine, the volume of which did not exceed 3 liters, they processed torque up to 310 Nm. Such boxes can be found on:
- Audi A4 B6 (2000–2006);
- Audi A4 C5 (2000-2004).
Car owners say that the newer the car, the more reliable the CVT installed on it. Initially, the Audi CVT control unit might need to be replaced after already 100 thousand kilometers. The reason for the failure of the unit was the oil in which the computer was floating. Lubrication during operation of the car was heated, destroying the unit. In 2003, the transmission design was finalized, which allowed us to cope with the problem.
For a CVT, overheating is dangerous, hot oil leads to failure of the control unit and irreversible damage to the solenoids-electric regulators.
For the box, the purity of the oil is more important. Dirty grease and a clogged filter lead to slow destruction of all transmission elements, which then require replacement.
If you drive in winter without first warming up the engine, then in the near future the clutches will go out of order, which will need to be replaced. A serious danger to the Audi CVT is towing other cars.
The tension of the drive chain most often occurs before the mileage of the car approaches 100 thousand km. It needs to be replaced during each overhaul, since even with slight stretching, the chain sliding along the cones can be broken, which leads to wear of the cones themselves and a drop in torque.
In addition, the Audi A4 gearbox is characterized by a sensitive differential, and therefore requires accurate control without sudden jerks, braking, etc.
Keep in mind that a failed differential is almost impossible to replace in a car service, replacement will be required for the Audi A4 variator as a whole.
Another common problem with Audi CVTs is the oil flowing through the axle shaft seals. You can cope with trouble by replacing the seals.
Experts say that checkpoint 01J is designed for about 200 thousand km. in case of regular maintenance, including replacement of gear oil and filter every 50 thousand kilometers.
2.0AN / Multitronic VL-380 .
In the period 2004-2009 the cars were equipped with 0AN variators (Multitronic VL-380). A transmission transmitting a torque of up to 380 Nm was installed on a car with turbocharged diesel ICEs and V6 engines.
PPC 0AN equipped with:
- Audi A4 B7 (2004–2008).
Car owners noted that overheating, dirty grease, towing are fatal for the Audi box.
The settling chips and metal dust clog the solenoids over time, the oil pressure decreases, the variator needs to be repaired with the replacement of all components.
A failed ejection pump and transmission fluid leakage are common problems that are typical of these Audi A4 boxes, which, fortunately, are quite easy to solve.
Stretching the chain is possible after 150 thousand kilometers, while it needs to be replaced as soon as possible, since otherwise the likelihood of wear of the variator cones increases.
Overhaul or replacement of the Audi A4 CVT will be required after about 200 thousand km, provided that the grease and filter are replaced every 55 thousand km.
3. 0AW / Multitronic VL-381.
In the period 2007–2016 the cars were equipped with a 0AW / Multitronic VL-381 gearbox, after which the VAG concern ceased to produce stepless gearboxes with a pulling belt.
0AW, whose torque was 400 Nm (this is the maximum value for CVTs), came to replace the outdated Audi A4 01J CVT.
They were equipped with:
- Audi A4 (2009–2016).
The most common CVT is 0AW for Audi A4 with a 2 liter TFSI engine.
This Audi gearbox allows for the use of a “sports” mode, which allows you to simulate an 8-speed classic hydraulic machine. Simulation occurs due to the use of the middle part of the cones and interruption of the transmission of torque. However, the service life of the drive chain when applying the mode is reduced.
During normal operation, the torque is still transmitted due to the entire surface of the cones.
These Audi transmissions feature a weak ejector pump and Teflon rings. The ECU valve channels clogged with dirty grease cause it to fail and the transmission to emergency mode. In some cases, the problem is solved by washing and cleaning.
The drive chain stretches for approximately 200 thousand kilometers, it needs to be quickly replaced, otherwise the cones can be destroyed. Cones cost about the same as the residual price of the car itself.
Towing a vehicle with a CVT is prohibited, as it threatens irreparable damage to the cones.
The variator resource before overhaul or replacement is about 200 thousand km., Subject to the timely replacement of oil and filter every 60 thousand km.
Audi A4 CVT malfunctions
As soon as you notice that something is wrong with the box, you should immediately call the tow truck. But first of all, it’s worth dialing the number of a specialized service that deals with the repair and replacement of Audi A4 variators, and get advice by reporting symptoms of malfunctions. An experienced specialist will tell you what to do.
Long-term operation of a problematic variator threatens with serious expenses for its repair, and possibly replacement. For example, during movement, there is a possibility of a broken belt, a “jamming” of the pump and, as a consequence, subsequent overhaul.
The failure of the box can be judged by:
- jolts / jerks when switching the transmission selector, extraneous noise;
- swimming revolutions at speed, indicating a slippage of the belt on the pulleys;
- vibrations (appearing at a speed of 50-60 km / h).
If at some point the car stops and does not move, then it is likely that the belt has broken.
First of all, they resort to computer diagnostics. Faulty mechatronics can be identified by errors reflecting the loss / decrease in pressure.
In the absence of errors, a transmission lubricant sample is taken. The clutches of the Audi A4 gearbox, when set on fire, give the smell of burnt oil. The amount of chips present in the oil is also evaluated. If it is insignificant, it is necessary to dismantle and disassemble the variator. After troubleshooting, look at the condition of the belt and pulleys, whether they need to be replaced.
Workers in a specialized service are aware of the main symptoms caused by a faulty belt, pulleys, starter pack, mechatronics and control unit.
1. Mechanical malfunctions Audi variator.
The main causes of the Audi A4 gearbox malfunction are related to mechanics, more precisely, to wear:
- starter pack.
Let us consider in more detail the wear of a chain whose resource is no more than 200 thousand km. Operation of a car with an extended chain will lead to serious damage to the cones and, as a result, to a significant increase in the price of repair work.
Sometimes it is possible to break off a very worn chain, in which case its parts, scattered along the transmission, can break the internal elements and clog the valve body. The cost of repair will increase at times, you may need to replace the Audi A4 variator.
For CVT gearboxes, overheated and dirty grease is a serious danger, therefore, oil and filter must be replaced every 50 thousand km.
In winter, driving an unheated car with a thickened gear lubricant will significantly increase the risk of failure of the starter pack clutches, which will need to be replaced.