If your vehicle's radio is equipped with an anti-theft system, make sure you know the correct activation code before disconnecting the battery. Before disconnecting the wire, refer to Section Anti-theft audio system and instrument panel language.
If a message in a different language appears on the instrument panel display after connecting the battery, refer to Section Anti-theft audio system and instrument panel language.
Withdrawal
1. Disconnect the negative battery cable.
2. Remove the exhaust system (see chapter Supply system).
3. Remove the cardan shaft (see chapter transmission line).
4. Disconnect the shift linkage (see Section Removal and installation of the switch lever).
5. Turn away bolts and remove arms of fastening of the case of the mechanism of a gear change. Before doing this, make sure that the linkage of the mechanism is completely disconnected.
6. Disconnect and remove the TDC sensor, RPM/Position sensor and reverse switch from the transmission, if applicable (see chapter Ignition system).
7. Remove the clutch slave cylinder (see chapter Clutch). Do not disconnect the clutch hydraulic hose. Secure the slave cylinder with wire.
Do not depress the clutch pedal when the slave cylinder is removed from the transmission. If the pushrod is forced out of the cylinder, the slave cylinder may be damaged.
8. Support the transmission with a transmission jack or roller jack and remove the support nuts.
9. Carefully lower the transmission/engine assembly until it rests on the cross member.
Never let an unsupported transmission hang on the transmission input shaft. This load will damage the clutch and clutch components.
10. Remove the bolts securing the transmission to the engine. Some bolts may have a bar head, these bolts require a special bar head.
11. Carefully separate the transmission from the engine. Make sure there is no load on the transmission input shaft. Lower the jack until there is enough room to remove the transmission from under the vehicle.
Installation
1. Installation is basically the reverse of removal. Be sure to lightly lubricate the input shaft splines with Microlube GL 261 or similar, then carefully install the transmission onto the engine.
Input shaft splines and clutch disc splines may not line up; in this case, turn the crankshaft pulley with a wrench to rotate the crankshaft slightly.
BMW recommends lubricating the splines of the clutch disc and transmission input shaft only with Microlube GL 261. Otherwise, the clutch disc may stick to the input shaft and shifting will be difficult. Microlube GL 261 available from BMW dealers (BMW Part No 81229407436).
If one of the transmission bolts has a socket head, be sure to install the washers; installing bolts without washers can cause the block heads to make such tight contact with the transmission case that it will be extremely difficult to remove them.
2. If the transmission has been drained of oil, be sure to fill it with the correct oil after installation.