Fig. 169. Sectional view of a four-speed gearbox.
If it is necessary to remove the engine, the gearbox is removed together with it, as described in section 2.1. To remove one gearbox, the following work must be performed:
Disconnect the ground cable from the battery.
Disconnect the clutch hydraulic hose and plug it to prevent brake fluid leakage.
Place the front of the car on stands.
Place a jack under the gearbox, placing a wooden spacer between the jack and the gearbox, and lift the gearbox.
Loosen the two bolts securing the intermediate support of the propeller shaft without unscrewing them completely.
Loosen the driveshaft clamping nut.
On 280S and 280SE models, loosen the exhaust system mounting nuts on the rear gearbox cover. Loosen the clamp nut and turn the pipe downwards.
Unscrew the crossmember and support fasteners on the gearbox; in 350 SE models, unscrew the lower protective mudguard and remove all parts.
Disconnect the gearbox control rods from the gearbox levers.
On 350 SE models, remove the connection between the two; exhaust pipes and the rear pipe together with the main and additional mufflers should be removed.
Loosen the tachometer mounting bolt in the rear gearbox cover and remove the shaft.
Disconnect the cardan shaft from the gearbox so that the elastic coupling remains on the gearbox flange.
Move the cardan shaft back as far as the intermediate support mount and clamping nut allow.
Place a wooden block under the front end of the cardan shaft, moving the shaft upward.
Disconnect the wires from the starter, unscrew the starter mounting bolts and remove the starter.
Loosen the bolts securing the clutch housing to the intermediate flange. Do not remove the two upper bolts. Mark which bolt the ground wire is attached to.
Move the gearbox horizontally backwards until it is removed from the mounting pins and the drive shaft comes out of the clutch driven disk hub. Turn the gearbox 45° so that the two starter mounting bosses in the clutch housing do not rest against the body floor tunnels, and lower the gearbox down.
During installation, perform the following tasks:
Lubricate the front end and splines of the gearbox drive shaft with long-life grease and position the gearbox horizontally against the engine. Install the slave cylinder and the clutch release drive hydraulic system pipeline on the clutch housing.
Engage the gear in the gearbox and, rotating the flange of the driven disk of the gearbox shaft in two directions, engage the splines on the drive shaft with the splines in the hub of the driven disk of the clutch. Then push the gearbox all the way toward the engine.
Secure the clutch housing to the intermediate flange of the engine. Install the ground wire under the head of the mounting bolt.
Install and secure the starter.
Screw in and tighten the clutch slave cylinder mounting bolts. Pay attention to the position of the slave cylinder spacer. Tighten the drive pipeline mounting and secure with a clamp.
Install and secure the tachometer drive.
Move the cardan shaft back and install its flange on the flexible coupling. Jack up the engine and gearbox to facilitate the connection of the cardan shaft flange and the flexible coupling.
Secure the exhaust pipes to the rear cover of the gearbox.
Install the powertrain suspension support on the gearbox and secure the rear crossmember to the body.
Install and secure the clamps on the exhaust system pipes.
Tighten the cardan shaft clamping nut to a torque of 30-40 Nm.
Install a protective splash guard under the intermediate support of the propeller shaft.
Perform the remaining work in reverse order.
Fill the gearbox with oil.