General Repair Information
Carefulness, cleanliness and the correct tools are required for transmission repairs to be successful. The usual basic safety precautions also apply when carrying out vehicle repairs.
Transmission
- Make sure that the alignment sleeves between the engine and transmission are positioned correctly when installing the transmission.
- Clean the contact surfaces when installing brackets and waxed components. Contact surfaces must be free of wax and grease.
- For the correct bolts and other components.
- Check the transmission fluid level. Refer to TRANSMISSION FLUID .
- For the correct capacities. Refer to TRANSMISSION/ENGINE ALLOCATION .
Seals, Sealing Rings
Thoroughly clean the separating surfaces and apply Sealing Paste.
Flange shaft, input shaft and selector shaft seals are illustrated as radial shaft seals.
Once a seal or gasket has been removed, check the contact surface on the housing or shaft for burrs and damage caused by the removal. Repair as necessary.
Before installing the shaft seal, lightly oil the outer circumference and fill the space between the sealing lips -arrow- halfway with Grease:G 052 128 A1 .
The open side of the seals point toward the fluid to be sealed in.
After replacing the seals and sealing rings, check the transmission fluid level and fill if necessary. Refer to TRANSMISSION FLUID .
Lightly lubricate O-rings before installing to prevent them from being crushed when inserting.
Sealant
- Always thoroughly clean the separating surfaces on the housing before applying the :Sealant .
- For the :Sealing Compound For allocation refer to the Parts information.
- Apply Sealing Compound evenly and not too thickly.
- Do not allow any Sealing Compound to get into the ventilation holes.
Fasteners
- Do not overstretch the circlips.
- Installed position for some of the circlips: the circlip is >>narrower at the top<<. This makes it easier for the pliers to grab the circlip when removing and installing it.
- Always replace damaged or stretched circlips.
- The circlips must fit completely inside the groove.
- Replace the adapter sleeves. Installed position: the slit -A- should align with the line of force -arrow-.
Bolts And Nuts
- Loosen the bolts and nuts opposite the tightening sequence.
- Nuts and bolts which secure covers and housings should be loosened and tightened diagonally and in steps if no tightening sequence is specified.
- Especially delicate parts, such as clutch pressure plates, must not be distorted. Loosen and tighten bolts and nuts in stages in a diagonal sequence.
- The tightening specifications stated apply to non-oiled nuts and bolts.
- Always replace self-locking nuts and bolts.
- Make sure the contact surfaces and visible surfaces on the nuts and bolts are waxed after assembling.
- Use a wire brush to clean the threads of bolts that were installed with locking compound. Next, use Locking Compound to install the bolts.
- Clean the threaded holes for the self-locking bolts or for the bolts coated with locking fluid. Otherwise there is a risk that the bolts will shear the next time they are removed.
- Please make sure that the thread pitch is correct so that the proper thread tap is used during cleaning, and the thread does not get damaged.
Bearings
- Insert the bearings with transmission fluid.
- Install the new tapered roller bearings. It is not necessary to oil them.
- Install needle bearings with lettered side (thicker metal) racing the fitting tool.
- Replace all the tapered roller bearings that are on the same shaft. Use tapered roller bearings from the same manufacturer.
- To install, warm the inner races/tapered roller bearing to approximately 100 °C (212 °F) with Inductive Heater:VAS6414 .
- Do not interchange outer and inner bearing races with those from other bearing of the same size. The bearings are paired.
Adjusting Shims
- Measure the shims at several locations with a micrometer caliper. It is possible to measure the necessary shim thickness by the different tolerances.
- Check for burrs and damage.
- Only install perfect shims.
Synchronizer Rings
- Do not interchange them. When reusing synchronizer rings, always install to the same gear wheel.
- Check for wear and replace if necessary.
- Check the grooves -arrow 1- on the synchronizer ring -A- and the inner race for flat areas (grooves are worn).
- The coating on the synchronizer rings must not be damaged.
- If an intermediate ring -B- is installed, check this intermediate ring on the outer friction surface -arrow 2- and inner friction surface -arrow 3- for >>grooves<<, >>wear grooves<< and >>blue coloring (from overheating)<<.
- Check taper of drive gear for >>grooves<< and >>scoring<<.
- Coat the synchronizing with transmission fluid and then install.
Toothed Gears, Synchronizer Hubs
- Clean and warm to maximum 100 °C (212 °F) using the Inductive Heat Unit:VAS6414 before installing.
- Pay attention to the installed location.
Selector Gears
- After assembling, check the selector gears for minimum axial clearance and ease of movement.
Clutch
- Do not tilt the clutch pressure plate. Loosen and tighten it diagonally and in small steps.
- To reduce odor caused by a burnt clutch, thoroughly clean the clutch housing and the flywheel running surface with a clean cloth.
- When removing transmission, remove the clutch slave cylinder without opening the lines.
- In the clutch slave cylinder with hydraulic lines attached is removed, the clutch pedal must not be pressed. Otherwise the piston will be pressed out of the clutch slave cylinder.