Chapter 6 Clutch

Easy, suitable fornovice with littleexperience

Fairly easy, suitablefor beginner withsome experience

Fairly difficult, suitablefor competent DIYmechanic

Difficult, suitable forexperienced DIYmechanic

Very difficult,suitable for expert DIYor professional

SpecificationsType Single dry plate with diaphragm spring, cable-operated

Clutch pedal travel 140 mmFriction plate diameter1124 cc and 1360 cc models:

Valeo clutch 181.5 mmLuk clutch 180 mm

1580 cc, 1761 cc and 1905 cc models 200 mm1998 cc models 215 mm

Torque wrench settings Nm lbf ftPressure plate retaining bolts 20 15Clutch pedal pivot bolt 25 18

The clutch consists of a friction plate, apressure plate assembly, a release bearingand the release mechanism; all of thesecomponents are contained in the large cast-aluminium alloy bellhousing, sandwichedbetween the engine and the transmission. Therelease mechanism is mechanical, beingoperated by a cable.

The friction plate is fitted between theengine flywheel and the clutch pressure plate,and is allowed to slide on the transmissioninput shaft splines. It consists of two circularfacings of friction material riveted in positionto provide the clutch bearing surface, and aspring-cushioned hub to damp outtransmission shocks.

The pressure plate assembly is bolted tothe engine flywheel, and is located by threedowel pins. When the engine is running, driveis transmitted from the crankshaft, via theflywheel, to the friction plate (thesecomponents being clamped securely togetherby the pressure plate assembly) and from thefriction plate to the transmission input shaft.

To interrupt the drive, the spring pressuremust be relaxed. On the models covered in

this manual, two different types of clutchrelease mechanism are used. The first is aconventional "push-type" mechanism, wherean independent clutch release bearing, fittedconcentrically around the transmission inputshaft, is pushed onto the pressure plateassembly. The second is a "pull-type"mechanism, where the clutch release bearingis an integral part of the pressure plateassembly, and is lifted away from the frictionplate.

On models with the conventional "push-type" mechanism, at the transmission end ofthe clutch cable, the outer cable is retained bya fixed mounting bracket, and the inner cableis attached to the release fork lever.Depressing the clutch pedal pulls the controlcable inner wire, and this in turn rotates therelease fork by acting on the lever at the fork'supper end, above the bellhousing. The releasefork then acts on the release bearing, pressingit against the fingers at the centre of thepressure plate diaphragm spring. Since thespring is held by rivets between two annularfulcrum rings, the pressure at its centrecauses it to deform so that it flattens, and thusreleases, the clamping force it exerts at itsperiphery, on the pressure plate.

On models with the "pull-type" mechanism,at the transmission end of the clutch cable,

the inner cable is attached to a fixed mountingbracket, and the outer cable acts against therelease fork lever. Depressing the clutch pedalpulls the outer cable towards the fixed end ofthe inner cable, and this in turn rotates therelease fork by acting on the lever at the fork'supper end, above the bellhousing. The releasefork then lifts the release bearing, which isattached to the pressure plate springs, awayfrom the friction plate, and thus releases theclamping force exerted at the pressure plateperiphery.

As the friction plate facings wear, thepressure plate moves towards the flywheel;this causes the diaphragm spring fingers topush against the release bearing, thusreducing the clearance which must be presentin the mechanism. To ensure correctoperation, the clutch cable must be regularlyadjusted.

1 The clutch adjustment is checked bymeasuring the clutch pedal travel.2 Ensure that there are no obstructionsbeneath the clutch pedal. Depress the clutchpedal fully to the floor, and measure thedistance that the centre of the clutch pedal

1 General information

2 Clutch - adjustment

61

ContentsClutch - adjustment 2 Clutch release mechanism - removal, inspection and refitting 6Clutch assembly - removal, inspection and refitting 5 General check See Chapter 1Clutch cable - removal and refitting 3 General information 1Clutch pedal - removal and refitting 4

Degrees of difficulty

62 Clutch

2.2 To check clutch adjustment, measurethe clutch pedal travel as described in text

pad travels through, from the at-rest positionto the floor (see illustration). If this is lessthan the distance given in the Specificationsat the start of this Chapter, adjust the clutchas follows.3 The clutch cable is adjusted by means ofthe adjuster nut on the transmission end ofthe cable. On some models, access to thelocknut is limited and, if required, the aircleaner duct or housing component can beremoved or disconnected to improve access.Refer to Chapter 4 for further information.4 Working in the engine compartment,slacken the locknut from the end of the clutchcable. Adjust the position of the adjuster nut,then re-measure the clutch pedal travel.Repeat this procedure until the clutch pedaltravel is as specified (see illustration).5 Once the adjuster nut is correctlypositioned, and the pedal travel is correctlyset, securely tighten the cable locknut. Wherenecessary, refit any disturbed air cleanerduct/housing components as described inChapter 4.

3 Clutch cable -removal and refitting

Removal1 Working in the engine compartment, fullyslacken the locknut and adjuster nut from theend of the clutch cable. On some models,

3.2b . . . and outer cable end fittings fromthe release lever and mounting bracket

3.2a Slacken the clutch cable locknut andadjuster nut, then free the inner cable end

fittings...

access to these nuts is limited and, ifrequired, the air cleaner duct or housingcomponent can be removed or disconnectedto improve access. Refer to Chapter 4 forfurther information.2 Release the inner cable and outer cablefittings from the clutch release lever andmounting bracket, and free the cable from thetransmission housing (see illustrations).3 Working inside the vehicle, release thefasteners by turning them through a quarter ofa turn, and remove the driver's side lowerfacia panel. Remove the heater duct which issituated behind the panel.4 Release the facia felt undercover retainingclips, and peel back the material to gainaccess to the upper end of the clutch pedal.5 Depress the metal retaining clip, and freethe inner cable from the plastic retainer fittedto the upper end of the clutch pedal (seeillustration).6 Return to the engine compartment, andwithdraw the cable forwards through thebulkhead, releasing it from any relevantretaining clips and guides. Note its correctrouting, and remove it from the vehicle.7 Examine the cable, looking for worn end

3.5 Depress the clutch pedal retainerclip (1) and release the inner cable end

fitting (2) from the pedal

fittings or a damaged outer casing, and forsigns of fraying of the inner wire. Check thecable's operation; the inner wire should movesmoothly and easily through the outer casing..Renew the cable if it shows signs of excessivewear or any damage.

Refitting8 Apply a thin smear of multi-purpose greaseto the cable end fittings, then pass the cablethrough the engine compartment bulkhead.9 From inside the vehicle, engage the innercable with the plastic retainer on the clutchpedal, and check that it is securely retainedby the metal clip. Clip the felt undercoverback into position, then refit the heater duct,ensuring it is correctly located at both ends,and install the lower facia panel.10 Refit the plastic locating collar to therelease lever, and ensure the rubber spacer iscorrectly located on the transmission end ofthe outer cable.11 Ensuring that the cable is correctly routedand retained by all the relevant retaining clips andguides, pass the lower end through the releaselever/mounting bracket (as applicable) andengage the inner cable. Refit the rubber spacerand flat washer to the end of the inner cable, andscrew on the adjuster nut and locknut.12 Adjust the clutch cable as described inSection 2.

4 Clutch pedal -removal and refitting

Removal1 Remove the pedal bracket assembly fromthe vehicle, as described in Chapter 9.2 With the pedal bracket assembly on thebench, slacken the nut, withdraw the clutchpedal pivot bolt, and separate the pedal andbracket. Slide the pivot bush and spring off the

2.4 Adjusting the clutch cable (air cleanerduct removed for clarity)

A cable that appearsserviceable when tested offthe car may well be muchheavier in operation when inits working position

Clutch 63

4.4a Press the pivot bushes into the pedalb o r e . . .

left-hand end of the pedal, and remove thespacer and pivot bushes from the pedal bore.3 Carefully clean all components, and renewany that are worn or damaged; check thebearing surfaces of the pivot bushes andspacer with particular care; the bushes can berenewed separately if worn.

Refitting4 Press the pivot bushes into the pedal bore,then apply a smear of multi-purpose grease totheir bearing surfaces, and slide in the spacer.Install the spring and pivot bush on the end ofthe pedal pivot, ensuring that the inner end ofthe spring is correctly hooked over the pedal(see illustrations).5 Refit the pedal to the bracket, ensuring thatthe outer end of the pedal spring is correctlylocated in the slot on the pedal mountingbracket, and install the pivot bolt. Refit andtighten the pivot bolt nut (see illustrations).6 Check that the pedal pivots smoothly, thenrefit the pedal bracket assembly to the vehicleas described in Section 14 of Chapter 9.

4.4b . . . then insert the spacer . . .

5 Clutch assembly - removal,inspection and refitting

Warning: Dust created by clutchwear and deposited on the clutchcomponents may contain

asbestos, which is a health hazard. DONOT blow it out with compressed air, orinhale any of it. DO NOT use petrol orpetroleum-based solvents to clean off thedust. Brake system cleaner or methylatedspirit should be used to flush the dust intoa suitable receptacle. After the clutchcomponents are wiped clean with rags,dispose of the contaminated rags andcleaner in a sealed, marked container.Note: Although some friction materials mayno longer contain asbestos, it is safest toassume that they do, and to take precautionsaccordingly.Removal1 Unless the complete engine/transmissionunit is to be removed from the car andseparated for major overhaul (see Chapter 2),the clutch can be reached by removing thetransmission as described in Chapter 7,Part A.

4.5a Refit the pedal to the bracket,ensuring that the spring is correctly

engaged in the bracket, and hooked overthe pedal (arrowed)

2 Before disturbing the clutch, use chalk or amarker pen to mark the relationship of thepressure plate assembly to the flywheel.3 Working in a diagonal sequence, slackenthe pressure plate bolts by half a turn at atime, until spring pressure is released and thebolts can be unscrewed by hand.4 Prise the pressure plate assembly off itslocating dowels, and collect the friction plate,noting which way round the friction plate isfitted.InspectionNote: Due to the amount of work necessary toremove and refit clutchcomponents, it is usually considered goodpractice to renew the clutch friction plate,pressure plate assembly and release bearingas a matched set, even if only one of these isactually worn enough to require renewal. It isalso worth considering the renewal of theclutch components on a preventive basis ifthe engine and/or transmission have beenremoved for some other reason.5 Remove the clutch assembly.6 When cleaning clutch components, readfirst the warning at the beginning of thisSection; remove dust using a clean, dry cloth,and working in a well-ventilated atmosphere.7 Check the friction plate facings for signs ofwear, damage or oil contamination. If thefriction material is cracked, burnt, scored ordamaged, or if it is contaminated with oil orgrease (shown by shiny black patches), thefriction plate must be renewed.8 If the friction material is still serviceable,check that the centre boss splines are

4.4c . . . and refit the pedal spring

4.5b Install the pedal pivot bolt, andtighten it to the specified torque

unworn, that the torsion springs are in goodcondition and securely fastened, and that allthe rivets are tight. If any wear or damage isfound, the friction plate must be renewed.9 If the friction material is fouled with oil, thismust be due to an oil leak from the crankshaftleft-hand oil seal, from the sump-to-cylinderblock joint, or from the transmission inputshaft. Renew the seal or repair the joint, asappropriate, as described in Chapter 2 or 7,before installing the new friction plate.10 Check the pressure plate assembly forobvious signs of wear or damage; shake it tocheck for loose rivets or worn or damagedfulcrum rings, and check that the drive strapssecuring the pressure plate to the cover donot show signs (such as a deep yellow or bluediscoloration) of overheating. If the diaphragmspring is worn or damaged, or if its pressure isin any way suspect, the pressure plateassembly should be renewed.11 Examine the machined bearing surfacesof the pressure plate and of the flywheel; theyshould be clean, completely flat, and free fromscratches or scoring. If either is discolouredfrom excessive heat, or shows signs ofcracks, it should be renewed - although minordamage of this nature can sometimes bepolished away using emery paper.12 Check that the release bearing contactsurface rotates smoothly and easily, with nosign of noise or roughness. Also check thatthe surface itself is smooth and unworn, withno signs of cracks, pitting or scoring. If thereis any doubt about its condition, the bearingmust be renewed. On clutches with a "pull-type" release mechanism, this means that thecomplete pressure plate assembly must alsobe renewed.

64 Clutch

5.14 Ensure the friction plate is fitted thecorrect way around, then install the

pressure plate

Refitting13 On reassembly, ensure that the bearingsurfaces of the flywheel and pressure plateare completely clean, smooth, and free fromoil or grease. Use solvent to remove anyprotective grease from new components.14 Fit the friction plate so that its spring hubassembly faces away from the flywheel; theremay also be a marking showing which wayround the plate is to be refitted (see illustration).15 Refit the pressure plate assembly,aligning the marks made on dismantling (if theoriginal pressure plate is re-used), andlocating the pressure plate on its threelocating dowels. Fit the pressure plate bolts,but tighten them only finger-tight, so that thefriction plate can still be moved.16 The friction plate must now becentralised, so that when the transmission isrefitted, its input shaft will pass through thesplines at the centre of the friction plate.17 Centralisation can be achieved by passinga screwdriver or other long bar through thefriction plate and into the hole in thecrankshaft; the friction plate can then bemoved around until it is centred on the

A clutch-aligning tool can be used toeliminate the guesswork when fitting afriction plate; these can be obtainedfrom most accessory shops). A home-made aligning tool can be fabricatedfrom a length of metal rod or woodendowel which fits closely inside thecrankshaft hole, and has insulating tapewound around it to match the diameterof the friction plate splined hole.

5.18 Once the friction plate is centralised,tighten the pressure plate retaining bolts

to the specified torque18 When the friction plate is centralised,tighten the pressure plate bolts evenly and ina diagonal sequence to the specified torquesetting (see illustration).19 Apply a thin smear of molybdenumdisulphide grease to the splines of the frictionplate and the transmission input shaft, andalso to the release bearing bore and releasefork shaft.20 Refit the transmission as described inChanter 7 Part A

6.7a Clip the lower pivot bush into positionin the transmission housing . . .

6.7b . . . locate the release fork shaft in thelower bush . . .

6.7c . . . and slide the upper pivot downthe release fork shaft, and into position in

the transmission housing -BE3 transmission shown

must be renewed. On models with a "pull-type" release mechanism, this means that thecomplete pressure plate assembly must berenewed, as described in Section 5.Refitting6 Apply a smear of molybdenum disulphidegrease to the shaft pivot bushes and thecontact surfaces of the release fork.7 Locate the lower pivot bush in thetransmission, ensuring it is securely retainedby its locating tangs, and refit the release fork.Slide the upper bush down the shaft, and clipit into position in the transmission housing(see illustrations).8 On models with a conventional "push-type"release mechanism, refit the release lever tothe shaft. Align the lever with the shaft hole,and secure it in position by tapping a new rollpin fully into position. Slide the releasebearing onto the input shaft, and engage itwith the release fork.9 Refit the transmission as described inChapter 7, Part A.

6 Clutch release mechanism -removal, inspection and refitting

Note: Refer to the warning concerning theclangers of asbestos dust at the beginning ofSection 5.Removal1 Unless the complete engine/transmissionunit is to be removed from the car andseparated for major overhaul (see Chapter 2),the clutch release mechanism can be reachedby removing the transmission only, asdescribed in Chapter 7, Part A,2 On models with a conventional "push-type"release mechanism, unhook the releasebearing from the fork, and slide it off the inputshaft. Drive out the roll pin, and remove therelease lever from the top of the release forkshaft. Discard the roll pin - a new one must beused on refitting.3 On both types of clutch, depress theretaining tabs, then slide the upper bush offthe end of the release fork shaft. Disengagethe shaft from its lower bush, and manoeuvreit out from the transmission. Depress theretaining tabs, and remove the lower pivotbush from the transmission housing.Inspection4 Check the release mechanism, renewingany component which is worn or damaged.Carefully check all bearing surfaces andpoints of contact.5 When checking the release bearing itself,note that it is often considered worthwhile torenew it as a matter of course. Check that thecontact surface rotates smoothly and easily,with no sign of noise or roughness, and thatthe surface itself is smooth and unworn, withno signs of cracks, pitting or scoring. If thereis any doubt about its condition, the bearing