Schaeffler (UK) Ltd’s technical team advises how to replace a LuK clutch on a Mercedes C180 Kompressor Coupe, 1.8 Petrol 2003
The Mercedes C Class has been on our roads since 1993. In 2003, Mercedes introduced the C180 Sports Coupe range which has become an extremely popular and desirable car.
The car featured is a 1.8 Supercharged 2003 model, which had covered more than 140,000 miles and the customer had noticed a little clutch slip. When carrying out a visual inspection it was apparent that this is a straight-forward job that most independent workshops can carry out.
For this repair, the workshop equipment we advise is a two post ramp and a transmission jack.
With the vehicle placed on the ramp, it is advised to disconnect the negative battery lead for safety. There is no work to be carried out from the top side of the vehicle, so raise the ramp and remove the engine and gearbox under shields.
Disconnect the PAS pipe from the gearbox bell housing by removing the two TRX bolts (figure1). Disconnect the gearbox speed sensor multiplug located on the underside of the gearbox, disconnect the reverse light switch multiplug at the rear of the gearbox, remove the gearbox earth strap and now disconnect and completely remove the exhaust oxygen sensor.
Now disconnect the exhaust centre joint by removing the three bolts. which may be corroded (figure2).
Now remove the exhaust front pipe support bracket and the rear gearbox mounting, then disconnect the prop shaft from the gearbox and remove the rubber cushion drive unit noting the position and colour of the bolts and washers as they have different locations (figure3).
Disconnect the hydraulic clutch pipe. The easiest point for this is where the hydraulic pipe comes through the transmission tunnel on the O/S. Once disconnected, the pipe connection needs to be blanked to prevent the fluid leaking out.
Remove both parts of the gear linkage, part one, by removing the plastic cover from the linkage housing and then removing the cable by releasing the ball joint (figure4), part two, by removing the retaining pin from the selector rod above the output flange and disconnecting.
At this point, block/support the prop shaft and linkages using the cross member to give clearance around the rear of the gearbox.
Support the gearbox with a transmission jack and remove the ten bell housing TRX bolts – all bell housing bolts can be accessed from the underside, with the use of a long extension bar. Ease the gearbox back until it is clear of the clutch and then lower and remove. The gearbox may be tight on the dowels so ensure the dowels remain in the engine and not the bell housing.
With the gearbox removed, an initial inspection showed the clutch was at its end limit as the three little adjustor ring springs were fully extended (figure5). Remove the clutch assembly and test the Dual Mass Flywheel (DMF) for play and rock. Information is available via REPXPERT, Schaeffler’s on-line catalogue and Schaeffler’s DMF Checkpoint app.
Remove the Concentric Slave Cylinder (CSC) from the bell housing, clean the bell housing and fit the new CSC. Clean the flywheel face to remove the ‘glaze’ (we used Emory cloth). Now it is good practice to try the new clutch plate on the gearbox input shaft to ensure the splines are correct and to lubricate the clutch splines with a small amount of high melting point grease so we there’s an even smear and any excess is wiped off.
Fit the new clutch assembly using the correct Clutch Alignment Tool and checking the clutch plate is the correct way round showing Getriebe Seite (Gearbox Side) on the outer face. We advise installing the clutch assembly with a Self Adjusting Clutch fitting tool. Ensure the gearbox bell housing dowels and the separator plate are still located properly.
Refit all parts in reverse order and torque to manufacturer’s specification. When bleeding the clutch hydraulic system, connect a bleed bottle to the bleed nipple with a hose and open the bleed nipple, this system is gravity bled, ensure the clutch master cylinder does not run dry. Reconnect the battery lead and ensure all electrical systems work correctly, radio, central locking etc. Once the car has been road tested and checked, the job is complete.
In addition to LuK clutch products, the company also supplies INA tensioners and FAG wheel bearings to the independent aftermarket, and recently introduced the Ruville engine, cooling and suspension components range. All brands are backed by technical support and repair installation tips through REPXPERT (www.repxpert.co.uk) and a technical hotline is also available; Tel: + 44 (0)1432 264264.