Components
Components
Special Tools
Proper tools and the maximum possible care and cleanliness are essential for successful transmission repairs. The usual basic safety precautions also naturally apply when carrying out vehicle repairs.
A number of generally applicable instructions for the various repair procedures - which were previously repeated at numerous places in this repair information - are summarized under the designation "Components", refer to => [ Components ] Components. They apply to the work described in this repair information.
Transmission
• Select the correct bolts and other components according to transmission code letters from the. Refer to => [ Code Letters, Allocation, Transmission Ratios, Capacities ] Code Letters, Allocation, Transmission Ratios, Capacities.
• When installing a new transmission, check the oil level and fill up with oil if necessary. Refer to => [ Transmission Oil Level Checking ] Service and Repair.
• Capacities and specifications, refer to => [ Code Letters, Allocation, Transmission Ratios, Capacities ] Code Letters, Allocation, Transmission Ratios, Capacities.
• Thoroughly clean all joints and surrounding areas before disassembling.
• When installing transmission make sure dowel sleeves are correctly seated.
Sealants
• Thoroughly clean joint surfaces on transmission housing etc. before applying sealing paste.
• Apply sealing paste (AMV 188 001 02 ) evenly and not too thick.
• Breather holes must remain free of sealing paste.
O-rings, Oil Seals, Gaskets
• Always install new O-rings, oil seals and gaskets.
• After removing gaskets and seals, always inspect the contact surface on the housing or shaft for burrs resulting from removal or for other signs of damage.
• Thoroughly clean housing joint surfaces before assembling.
• Before installing oil seals, lightly oil the outer circumference of the seal and fill the space between the sealing lips - arrow - about half full with grease (G 052 128 A1).
• The open side of the oil seals face the side with fluid filling.
• When installing a new oil seal, position the seal in the housing so that sealing lip does not contact the shaft in the same place as the old seal (make use of insertion depth tolerances).
• Lightly oil O-rings before installing to prevent them from being trapped and damaged when assembling.
• After replacing seals and gaskets, check and, if necessary, top off oil level in transmission. Refer to => [ Transmission Oil Level Checking ] Service and Repair.
Locking elements
• Do not overstretch circlips.
• Always replace circlips which have been damaged or over-tensioned.
• Locking rings and/or circlips must be properly seated in the base of the groove.
• Replace spring pins. Position: slit - A - should be in line with the line of force - arrow -.
Nuts, Bolts
• Loosen the nuts and bolts in reverse sequence to the specified tightening sequence.
• Nuts and bolts which secure covers and housings should be loosened and tightened in diagonal sequence and in stages if no tightening sequence is specified.
• Loosen and tighten particularly sensitive parts in diagonal sequence and in stages, taking care to keep them straight.
• The tightening specifications stated apply to non-lubricated nuts and bolts.
• Always replace self locking bolts and nuts.
• Clean the threads of bolts which are secured by a locking compound with a wire brush. Then lubricate bolts with locking compound (AMV 185 101 A1) again before installing.
• Threaded holes which take self locking bolts or bolts coated with locking compound must be cleaned (using a tap or similar). Otherwise there is a danger of the bolts shearing when subsequently being removed.
Shims
• Use a micrometer to measure the shims at several points. Tolerance variations make it possible to obtain the exact shim thickness required.
• Check for burrs and damage.
• Only install perfect, undamaged shims.
Bearings
• Install new tapered roller bearings as supplied; do not additionally lubricate with oil.
• Lubricate all bearings (except tapered roller bearings) with gear oil before installing in transmission.
• Heat inner races of tapered roller bearings to approximately 100 °C before installing. Press in onto stop when installing so there is no axial clearance.
• Do not interchange the outer or inner races of bearings of the same size (the bearings are paired).
• If required, replace the tapered roller bearings on one shaft together and use new bearings from a single manufacturer.
• Install needle bearings so the lettering (side with thicker metal) faces the installing tool.
• Grease needle bearing for transmission input shaft in rear of flywheel.
Synchronizer Rings
• Do not interchange synchronizer rings. When reusing always install to the same gear.
• Check for wear; replace if necessary.
• Lubricate with gear oil before installing.
Gear Wheels and Synchronizing Hubs
• Before installing, clean and heat on a hotplate to 130 °C (maximum).
• Press in onto stop when installing so there is no axial clearance.
• The temperature can be measured with temperature tester (VAG 1558), ignition tester (VAG 1767 ) or diesel tester (VAG 1743).
• Note installation position.
Selector Gears
• After installing, check 1st to 6th selector gears for minimal axial play and freedom of movement.
Clutch Actuation
• When removing transmission, remove clutch slave cylinder without disconnecting lines.
• Do not depress the clutch pedal after removing the clutch slave cylinder if the hydraulic line is still connected. Otherwise the piston will be pressed out of the clutch slave cylinder. As a result the clutch slave cylinder will be destroyed.
• If the clutch pedal does not return to its initial position after releasing it, you must bleed the clutch system (further measures, refer to => [ Master Cylinder and Slave Cylinder ] Master Cylinder and Slave Cylinder).
• The clutch system should be bled at the same intervals as the brake system.
• Make sure that the pressure plate is kept straight: loosen and tighten bolts in a diagonal sequence and in several gradual stages (does not apply to SAC pressure plates).
• Note assembly instructions for Self Adjusting Clutch (SAC) pressure plate. Refer to => [ Clutch with SAC Pressure Plate ] Clutch With SAC Pressure Plate.
• On vehicles with SAC pressure plate an adjuster ring has to be reset when only the clutch plate is replaced. Refer to => [ SAC Clutch Pressure Plate Adjuster Ring Adjusting ] Adjustments.
• If the clutch has burned out, thoroughly clean the bellhousing, flywheel and parts of the engine facing the transmission in order to prevent odors.