General Repair Information
The highest level of care and cleanliness along with tools that function properly are required to ensure a proper and successful transmission repair. The usual basic safety precautions apply when making vehicle repairs.
Some general repair information for individual repair procedures, that appear many times throughout the repair information, is summarize here. They apply to this repair information.
Special Tools
Refer to Workshop Equipment and Special Tools for a complete list of special tools used in the repair information.
Transmission
- Make sure that the alignment bushings between the engine and transmission are positioned correctly when installing the manual transmission.
- Clean the contact surfaces when installing the mounting brackets as well as parts that have been waxed. Contact surfaces must be free of wax and grease.
- Allocate the bolts and other components. Refer to the Parts Information.
- Fill the transmission fluid when repairing the manual transmission.
Seals and Gaskets
- Thoroughly clean the separating surfaces and apply Sealing Paste.
- Flange shaft, input shaft and selector shaft seals are illustrated as radial shaft seals.
- After removing seals and gaskets, check the contact surfaces on the housings or shafts for burrs and damage caused by the removal. Repair as necessary.
- Fill the space between the sealing lips halfway with Grease -arrow- before installing the radial shaft seal.
- The open side of the gaskets point toward the fluid to be sealed in.
- Lightly lubricate the O-rings before inserting to prevent the rings from being crushed during assembly.
Sealant
- Always thoroughly clean the separating surfaces on the housing before applying the Sealing Compound.
- Apply Sealing Compound evenly and not too thickly.
- Do not allow any Sealing Compound to get into the bleed holes.
Circlips
- Do not stretch the circlips.
- Installation position for some of the circlips: the circlip is >>narrower at the top<< and so is its installation position. 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 rest at the bottom of the groove.
- Replace the adapter sleeves. Installation position: the slot -A- should align with the line of force -arrow-.
Bolts and Nuts
- Always loosen or tighten bolts and nuts on covers and housings diagonally.
- Especially delicate components, such as clutch pressure plates, must not be distorted. Loosen and tighten bolts and nuts in stages in a diagonal sequence.
- The tightening specifications given apply to unoiled bolts and nuts.
- Replace self-locking bolts and nuts after removing them.
- 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 the bolts that were installed with locking fluid. Next, use Locking Compound to install the bolts.
- Use a thread cutter to clean all threaded holes containing self-locking bolts to remove any locking compound residue. Otherwise the bolts could shear the next time they are removed.
- Please make sure that the thread pitch is correct so that the proper thread cutter 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 the lettered side (thicker metal) facing the fitting tool.
- Replace all the tapered roller bearings that are on the same shaft, and use tapered roller bearings from the same manufacturer.
- To install, warm the inner races to approximately 100 °C (212 °F) with the Inductive Heater:VAS6414 .
- Do not interchange outer and inner bearing races with those from other bearing of the same size. The bearings are paired.
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 or damage.
- Only install perfect shims.
Synchronizer Rings
- Do not interchange them. When reusing synchronizer rings, always install on the same gear assembly.
- 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 the gear assembly taper for >>wear grooves<< and >>scoring<<.
- Coat the synchronizing with transmission fluid and then install.
Toothed Gears, Synchronizer Hubs
- Before installing, clean and warm to a maximum of 100 °C (212 °F) using the Inductive Heater:VAS6414 .
- Pay attention to the installation position.
Gear Assemblies
- After assembling, check the gear assemblies 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.