Audi Workshop Service and Repair Manuals

• ◆ In addition to the familiar manual gearboxes with aluminium housings, the Audi A4 may be fitted with a manual gearbox featuring a housing made of a magnesium alloy. Identification markings .
• ◆ Bolts and other components which have direct contact with the gearbox housing have a surface which is matched to the gearbox housing depending on whether it is manufactured from aluminium or magnesium.
• ◆ If the incorrect components (bolts, nuts, washers etc.) are used this will cause contact corrosion. The gearbox housing will be damaged.
• ◆ The gearbox housing, gearbox cover and differential cover must also all be of the same material.
• ◆ If you are not sure whether used parts can be refitted, always fit new parts.

Distinguishing features of magnesium gearboxes:

→ The identification marking >Mg Al 9 Zn 1<can be found near arrows 1 and 2 on gearboxes with a magnesium housing.

The gearbox code letters also indicate whether a gearbox has a magnesium housing => from Page 00-3.