General repair instructions

The maximum possible care and cleanliness and proper tools are essential to ensure satisfactory and successful transmission repairs. The usual basic safety precautions naturally also apply when carrying out vehicle repairs.

A number of general instructions for individual repair procedures - otherwise listed several times in many places in the article - are grouped together in the following paragraphs and apply to this article.

Transmission 

• When replacing manual transmission, check oil level and top up as necessary. Refer to Transmission oil level, checking .
• Capacities and specifications. Refer to Code letters, assignment of mechanical units, transmission ratios and capacities  onward
• When replacing rear final drive, check and adjust oil level in rear final drive as necessary:

Refer to 39 FINAL DRIVE, DIFFERENTIAL

• Carefully clean all joints and adjacent areas before disconnecting.
• When installing transmission ensure proper seating of the dowel sleeves.

O-rings, oil seals, gaskets 

• Always replace O-rings, oil seals and gaskets.
• After removing gaskets, examine contact surface on housing/shaft for burrs resulting from removal or for other signs of damage.
• Carefully clean sealing surfaces of housing before assembly.

Fig 1: Identifying Space Between Oil Seal Sealing Lips

Courtesy of VOLKSWAGEN UNITED STATES, INC.

• Before installing radial shaft oil seals, lubricate outer diameter slightly and half fill space between sealing lips (arrow) with sealing grease G 052 128 A1.
• Open side of oil seal faces fluid.
• Press in new oil seal such that sealing lip is not at same location as sealing lip of old oil seal (make use of insertion depth tolerance).
• Lubricate O-rings slightly beforehand to prevent their being pinched on assembly.

• Check oil level after replacing gaskets and oil seals. Refer to Transmission oil level, checking .

Sealant 

• Carefully clean sealing surfaces of housing before applying sealing paste.
• Apply sealing paste AMV 188 001 02 evenly and not too thickly.
• Sealing paste must not enter vent holes.

Locking elements 

• Take care not to overstretch circlips.
• Always replace damaged or overstretched circlips.
• Circlips must be properly positioned in groove.

Fig 2: Identifying Locking Elements

Courtesy of VOLKSWAGEN UNITED STATES, INC.

• Replace spring pins. Installation position: Slot -A- in line with direction of force (arrow).

Nuts and bolts 

• Remove nuts and bolts in reverse of tightening sequence.
• Loosen and tighten nuts and bolts for securing covers and housings in diagonal sequence.
• Particularly delicate parts - e.g. clutch pressure plates - must be kept straight and should be loosened off and tightened gradually in diagonal sequence.
• Tightening torques specified apply to non-lubricated nuts and bolts.

• Always replace self-locking nuts and bolts.
• Clean threads of bolts screwed in with a locking agent with a wire brush. Then install bolts using AMV 185 101 A1.
• Threaded holes which held self-locking bolts or bolts with locking agent need to be cleaned (e.g. using a thread tap). Otherwise bolts will be at risk of stripping when removed.

Bearings 

• Install needle bearings with labelled side (thicker metal) facing installation tool.
• Grease needle bearing for rear transmission input shaft in flywheel.
• Lubricate all bearings for installation in transmission housing with gear oil.
• Heat inner races of tapered roller bearings to approx. 100 ° C before installing. Press home as far as stop on assembly so that there is no axial clearance.

• Never confuse outer and inner races of bearings of the same size.
• Always replace tapered roller bearings on one shaft together, and use parts from the same manufacturer.
• Tapered roller bearings in the transmission for the output shaft and differential are low-friction. Do not treat new tapered roller bearings with oil before the friction torque measurement. The bearings have been treated with a special oil at the factory for this purpose.

Shims 

• Perform a dimensional check at several points on shims using a micrometer. Different tolerances make it possible to obtain the exact shim thickness required.
• Check for burrs and damage.
• Only install undamaged shims in perfect condition.

Gears, synchro-hubs, inner races for sliding gears 

• Heat gears and sychro-hubs to approx. 100 ° C before installing. Press home as far as stop on assembly so that there is no axial clearance.
• Heat inner races for sliding gears to approx. 100 ° C before installing.
• The temperature can be checked using temperature probe V.A.G 1558.
• Note installation position.

Sliding gears 

• After installation check sliding gears for 1st to 5th gear and sliding gear for reverse gear for axial clearance of 0.15 to 0.35 mm and check for ease of movement.

Synchro-rings 

• Do not confuse synchro-rings, assign to the same gear wheel when re-using.
• Check for wear and replace if necessary.
• Apply transmission oil before installing.

Clutch mechanism 

• For removal of transmission remove clutch slave cylinder without opening hydraulic circuit.
• If slave cylinder is removed with hydraulic pipe attached, do not depress clutch pedal. Otherwise piston will be pushed out of slave cylinder.
• Make sure clutch pressure plate is kept straight; loosen and tighten bolts gradually in a diagonal sequence.
• To reduce the odor nuisance of a scorched clutch, thoroughly clean bell housing, flywheel and parts of engine facing transmission.