Contents: KP ⬇ Mechatronics ⬇ Seals, O-rings ⬇ Oil and filter for gearbox with…⬇ Threaded plug for draining, filling…⬇ Transfer case oil ⬇ Haldex clutch oil and rear final…⬇ Location of oil fill and drain holes…⬇ Retaining rings ⬇ Screws, nuts ⬇ Support ⬇ Adjusting washers ⬇ Electrical units ⬇ Guided troubleshooting ⬇ Cleanliness rules ⬇
KP
Make sure that no dirt gets into the "open" gearbox. In particular, if the Mechatronic unit of the DSG "J743" gearbox and/or the oil pump are "disconnected", dirt can get into the gearbox and cause it to fail. If the gearbox cover is removed or there is no oil in the gearbox, do not start the engine or tow the vehicle. First, thoroughly clean the connection points and their surroundings and only then disconnect. When installing the gearbox, pay attention to the correct position of the relief bushings between the engine and the gearbox. Place the removed parts on a clean lining and cover them so that they do not get dirty. Do not use lint-free fabrics! Install only clean parts: Remove original parts from the packaging only immediately before installation. Carefully cover or close open components unless the repair is urgent. If the gearbox has been replaced, check the oil level,
Mechatronics
The mechatronic unit is identified by the letter designation of the gearbox.
Seals, O-rings
After removing the seals, check the mating surfaces of the housings or shafts for burrs and damage and remove them. Before installing the radial shaft seal, apply sealing grease to the working edges and the space between them and lubricate along the outer perimeter with dual clutch transmission oil. The open side of the radial shaft seal faces the oil. Replace the sealing rings, lip seals and gaskets. Lightly lubricate the circular sealing rings with DSG oil before installation to avoid damage to the rings during installation. It is imperative to use only DSG oil in the oil area. Other lubricants lead to malfunctions of the hydraulic control of the gearbox. Check the oil level after installation.
Oil and filter for gearbox with front final drive
The quality of the oil has a decisive influence on the functioning of the gearbox. The oil not only lubricates the gearbox, but also transfers small wear products from the differential to both filters, maintains a lubricating film on the differential gears and, at the same time, is the working fluid of the hydraulic gearshift drive. In addition, the oil seals the gate and helps the locking rings of the synchronizers, promotes smooth gear shifting, accumulates and removes heat, and minimizes noise. The oil performs many functions. To maintain these functions, it is necessary to replace not only the oil, but also the oil filter on the gearbox during maintenance. Replace the oil filter - "yes or no". The filter must be replaced if: the maintenance interval has expired; coolant got into the oil; metal shavings found in oil; the clutch has burned out or has mechanical damage. Do not replace the filter if: the transmission oil cooling radiator has been replaced, but the coolant has not entered the oil; the shift control shaft sealing ring was replaced; the flange or insert shaft seal ring has been replaced; the leaky mechatronics, clutch or oil pump cover was replaced. The input shaft torque sensor "G182" and the clutch temperature sensor "G509" were replaced.
Threaded plug for draining, filling and checking the oil level in the gearbox
the 6-speed DSG gearbox and front main gear have a common filler hole and are filled simultaneously. Checking the level and changing the oil is carried out through the inspection hole "arrow".
Note: Behind this plug there is a plastic bypass tube, which is tightened with a 3 mm Allen key to a torque of 3 Nm. The length of the bypass tube determines the oil level in the gearbox; when replacing this tube, observe the part number.
Transfer case oil
The angular transmission is equipped with an automatic oil filling system for the main gears.
Caution! Risk of damage to the transfer case. The main gears may only be filled with the oil specified as a spare part. Using other oils may result in malfunction or failure of the angular gear.
Haldex clutch oil and rear final drive oil
Caution! The rear final drive and the Haldex clutch have separate "oil circuits". The Haldex clutch is filled with special oil for Haldex clutches. The rear final drive is filled with "oil for final drives".
Location of oil fill and drain holes in rear final drive with Haldex clutch
A. Oil filler plug for high performance oil for Haldex couplings
B. Oil drain plug for high performance oil for Haldex couplings
1. Filler plug for main gear oil
2. Drain plug for final drive oil
Retaining rings
Do not overtighten the retaining rings. Replace damaged or stretched retaining rings. The retaining rings must rest against the bottom of the groove.
Screws, nuts
Loosen and tighten the screws or nuts for fastening the covers and crankcase in stages in a cross pattern. Tightening torques are given for unlubricated screws and nuts. Clean the threads of screws that are tightened with locking agents with a wire brush. Then screw in the screws with locking agents -AMV185101 A1-. All threaded holes into which the screws with locking agent were screwed in must be cleaned with a tap from the remains of the locking agent. Otherwise, there is a risk of the screws being damaged during subsequent dismantling. Replace screws that are tightened by turning to a specified angle, as well as self-locking nuts.
Support
Always install needle bearings with the label side up (greater thickness) to the pressing mandrel. Before installation, lubricate all bearings with engine oil.
Adjusting washers
Measure the adjusting washers in several places with a micrometer. Different tolerances allow you to accurately select the washer of the required thickness. Check for scratches and damage. Install only serviceable ones (undamaged) adjusting washers
Electrical units
When touching metal objects, an electrostatic discharge may occur. The reason is the electrostatic charge of the human body. When touching the electrical components of the gearbox and the switching mechanism, this electrostatic charge can lead to malfunctions. Before working with electrical components, touch a grounded object, such as a water pipe or a lift. Do not directly touch the connector contacts. Disconnect the battery.
Guided troubleshooting
Before starting repair and restoration work on the control unit, it is necessary to perform a troubleshooting search using the "Guided troubleshooting".
Cleanliness rules
Thoroughly clean the connection points and their surroundings before disconnecting. Install only clean parts: Remove parts from packaging only immediately before installation. Replace cardboard gaskets. Remove all seals completely, thoroughly clean all sealing surfaces, Place removed parts on a clean lining and cover to prevent contamination. Use film and paper. Do not use loose rags! Carefully cover or seal open components unless repairs are urgent. Protect disconnected electrical connectors from dirt and moisture and only connect them when dry.