June 2021

36 AFTERMARKET JUNE 2021 CLUTCH AND TRANSMISSION www.aftermarketonline.net T he customer complained they experienced clutch slip when accelerating, a fault that was confirmed with a short road test, so the clutch replacement was authorised, along with a DMF, if required due to the mileage of the vehicle. The X3 shares the same platform as the 3 Series, so if you’ve replaced a clutch on one of these, everything will look pretty familiar, the only major difference being a transfer box on the back of the gearbox, which houses a computer controlled clutch that splits the drive 40/60 front to back, with the capability of sending the drive 100% to either front or rear axles. With the full repair instructions available on the REPXPERT workshop information portal and a book time of 3.4 hours, this makes a great repair for any independent workshop. Workshop equipment Vehicle lift, (two-post or wheel free is ideal) Gearbox jack Tall axle stand or similar BMW clutch alignment tools Secure With the vehicle placed on the lift, raise the vehicle to gain access to the underside, remove the engine and gearbox undertrays, and stow safely, then remove the four bolts that secure the floor brace to the body under the gearbox and take off the brace. Support the rear of the exhaust with a tall axle stand, remove the exhaust mountings and the exhaust front pipe brackets from the lower bell housing and then ease the exhaust system to the O/S of the vehicle while still on the axle stand (Fig.1), now take off the heat shield that is positioned between the exhaust and the prop shaft. Remove the front prop shaft (Fig.2). It is always Alistair replaces the clutch and DMF in a 2005 BMW X3 2.0 diesel that has covered over 162,000 miles CASE STUDY: CLUTCH REPLACEMENT advisable to mark the position of the prop shaft/flanges to avoid balance issues following reassembly. Also mark the position of the rear prop shaft to gearbox flange, detach it from the gearbox flange and remove the centre bearing (Fig.3), then tie the prop shaft to the side. Support Disconnect the wiring loom from the back of the gearbox and the reverse light switch on the side, then place a gearbox jack under the gearbox to support it, detach the rear gearbox mounting and lower the gearbox, which will now provide access to the gear stick linkage. Take off the pin retaining clip and pin and disconnect the linkage from the gearbox. Remove the two nuts from the clutch slave cylinder (Fig.4), detach the slave cylinder from the gearbox and secure away from the gearbox. Working around the bell housing, remove the bell housing bolts, but note there is a smaller bolt inserted from the back of the engine into the housing. When all bolts have been removed, ease the gearbox away from the engine and when clear, lower the gearbox and place it safely to one side. With the clutch now visible, it was possible to confirm that the clutch had reached the end of its service life as the adjuster springs were fully extended (Fig.5). Un-bolt the clutch cover, remove the clutch cover and plate assembly, the DMF was then tested and had excessive rotational free play, so was also replaced. All dual mass flywheel test information is available through REPXPERT and the REPXPERT app under Checkpoint. BY Alistair Mason, Schaeffler REPXPERT Fig 1