flywheel FIAT PUNTO 1998 176 / 1.G Owner's Guide

7B*2 Automatic transmission
disconnected. As the magnetic field increases, the powder sticks together, and the coupling between Ihe elements becomes Increasingly rigid. 7 Selection of reverse, neutral and forward gears is by the movement of a sliding sleeve on a hub keyed to the drive pulley shaft. In forward gear, the sleeve engages with the gear on the end of the input shaft, which is then locked to the drive pulley shaft. When reverse is selected, the sleeve engages with reverse driven gear, which is in constant mesh with an idler gear driven by transfer gears from the input shaft gear. In neutral, the sleeve Is in an intermediate position, and the
two shafts are not connected. 8 Tho drive pulley and driven pulley both consist of fixed and moving halves. The movement of ihe drive pulley halves is controlled hydraulically, while the driven pulley halves move under the influence of a spring and the tension exerted by the drivebeit. As the drive pulley opens, the driven pulley closes, and vice-versa. In this way, the transmission ratio between the two pulleys can be varied. The ratios are continuously variable between preset limits; the difference between the lowest and highest ratios available is approximately 5:1. 9 Hydraulic pressure is generated by a gear-
type pump Inside the transmission. The punp driveshaft runs inside the Input and drive pulley shafts, and Is splined to the centred the engine flywheel. This means that hydreulc pressure is only generated when the engine is running, which is why a car with this type ot transmission cannot be push- or tow-started 10 Application of hydrautic pressure to the pulley halves is via a control unit, which receives information on accelerator pedal position, transmission selector lever position, transmission ratio currently in use, and drive pulley speed. From this information, the control unit determines whether, and in which direction, lo change the pulley ratios.
1.1 a Cutaway view of the ECVT (electronic continuously variable transmission) 7 Electromagnetic dutch 3 Drive pulley 5 Metal drivebeit 7 Hydraulic controt unit 2 Gear selector sleeve A Dnven pulley 6 Final drive reduction gears

7B*4 Automatic transmission
2 Automatic transmission - ^ removal and refitting St
Removal 1 Select a solid, level surface to park the vehicle upon. Give yourself enough space to move around it easily. Apply the handbrake then jack up the front of the vehicle and support on axle stands (see Jacking and vehicle support). Remove both front wheels, 2 Remove the battery and mounting tray as described In Chapter 5A. 3 Remove the air cleaner and air inlet duct as described In Chapter 4A. 4 Disconnect the kickdown cable at the sector on the throttle housing and detach It from the mounting on the camshaft cover. Also release the cable from the support on the left-hand end of the cylinder head. 5 Disconnect the wiring connectors on the transmission. 6 Disconnect the fluid inlet and outlet Unas from the heat exchanger on top of the transmission. 7 Pull the fluid level dipstick from Its tube on the front of the transmission and tape over the top of the tube to prevent dirt entry. 8 Unscrew and remove the retaining pin and disconnect the speed selector cable from the top of the transmission. 9 Unscrew the upper bolt securing the starter motor to the transmission. 10 Unscrew the upper bolts securing the transmission to the engine. 11 Support the weight of the engine using a hoist attached to the engine lifting eyes, or alternatively UBO a trolley jack and block of wood beneath the engine, 12 Remove the screws and remove the front wheel arch liner from under the left-hand wheel arch. 13 Unscrew the nut securing the earth cablo to the transmission. 14 Using a punch drive out the roll pins securing both driveshafts to the final drive output shafts. 15 Unscrew and remove the bolts securing the left-hand swivel hub assembly to the front suspension strut, then separate the components and support the swivel hub on an axle stand. 16 Move the swivel hub assembly outwards and slide the inner end of the driveshaft from the splines on the transmission output shaft. Support the shaft away from the transmission to prevent damage to the gaiters. 17 Unscrew the lambdafoxygen sensor from the exhaust downpipe and position it In a safe place to prevent damage. 18 Unscrew ihe nuts securing the downpipe to Ihe exhaust manifold, then lower It and suppon on an axle stand. Recover the gasket. 19 Unscrew the knurled nut and disconnect the speedometer cable from the top of the final drive housing.
3-2 Locking the flywheel when removing the electromagnetic clutch 20 Unscrew the remaining bolt securing the staner motor to the transmission 21 Unbolt and remove Ihe lower flywheel cover from the transmission. 22 Working beneath the vehicle, unscrew the bolts securing the rear engine mounting to the underbody then unscrew the bolts securing the mounting lo the transmission and withdraw the mounting assembly from under the vehicle. 23 Unscrew the bolts securing the left-hand engine/transmission mounting to the body thon unscrew the bolts from the transmission and remove the mounting. 24 Support the weight of the transmission on a trolley jack then unscrew the remaining nut and bolt from the bellhouslng and pull the transmission away from the engine. Lower it and remove from under the vehicle.

A


Warning: Support the transmission to ensure that It remains steady on the Jack head. Keep the transmission level until the Input shaft and pump shaft are fully withdrawn from the electromagnetic clutch housing.
Refitting 25 Refitting is a reversal of the removal procedure, but note the following points. a} Apply a smear of high-melting-point grease to the splines of the transmission input shaft and oil pump driveshaft.
3.6 Checking the resistance of the clutch windings 1 Slip rings
0) Tighten all nuts and bolts to the
specified
torque, where given, c) Renew both driveshaft roll pins.
3 Electro-magnetic clutch • & removal, inspection 5. and refitting ^
Removal 1 Remove Ihe transmission as described n Section 2. 2 Turn the flywheel so that two of the lour mounting bolts are accessible, Hold tha flywheel stationary then unscrew Ihe tvrt bolts. To hold the flywheel, Insert a wida bladed screwdriver In the ring gear teeth or alternatively use a piece of angle iron against one of the retaining bolts temporarily Inserted in the cylinder block (see illustration). 3 Turn the crankshaft half a turn and unscrew the remaining bolts, then withdraw the electromagnetic clutch.
Inspection 4 Turn the driven element by means of tha slip rings, and check that the bearing is not noisy or rough. 5 Inspect the slip rings for burning or other damage. Clean them if necessary using fid and a clean rag. 6 Check the resistance of the clutch windings, using an ohmmetor connected across the slip rings (see Illustration). The resistance at 20*0 should be 2 to 4 ohms. 7 Check the Insulation of the windings, using an ohmmeter connected between either sip ring and the body of the clutch (see illustration). Resistance should be Infinity. 8 If the clutch fails any of the foregoing checks, renew it. Apart from the brush gear, Individual spares are not available.
Refitting 9 Refitting is a reversal of removal but tighten all bolts to the specified torque.
windings