Clutch Replacement Guide
In this article, clutch supplier NAP highlight some important do's and don'ts when fitting a replacement clutch.
A) Always replace the complete clutch, ie. cover assembly, driven plate and release bearing.
B) Ensure that the correct parts are obtained - check against the original units before fitting.
C) Place the driven plate inside the cover assembly pressure plate the correct way round to ensure that no fouling occurs between the two components.
D) Always use a clutch alignment tool.
E) Never allow the weight of the gearbox to hang on the clutch components.
1) Check the spigot bearing/bush thoroughly for excessive wear and replace if necessary.
2) Examine all components for signs of oil contamination. Check engine and gearbox oil seals and replace if necessary.
3) Examine the old clutch plate splines for signs of excessive wear or damage - this may indicate previous gearbox misalignment.
4) Check the flywheel for run-out, scoring or cracking and excessive wear - abnormal and excessive clutch plate wear will occur unless this is corrected. If machining of the flywheel is undertaken, ensure that the same amount of material is removed from both friction and mounting surfaces. Flywheels with excessive wear should always be replaced.
5) Ensure that the clutch release mechanism operates freely, examine all release bearing mounting components (clutch release arm, cross shaft, bushes, bearings etc) for excessive wear or damage. Replace all substandard parts.
6) Ensure that all contact surfaces are in good condition, and that oil or grease is not allowed to contaminate the contact surfaces. Always remove any protective coating that may be applied to the clutch cover pressure plate.
7) Ensure that the driven plate is not damaged prior to fitting, lightly grease the spline and ensure that the driven plate slides freely on the gearbox spline. Take care not to damage the spline on fitting.
8) Ensure that the driven plate is fitted the correct way round.
9) Use an alignment tool to position the driven plate centrally during fitment, do not remove the tool until all the cover assembly bolts have been tightened.
10) When re-fitting the cover assembly to the flywheel, the mounting bolts must be tightened diagonally and not in rotation. Ensure that the cover is located correctly onto the dowels and that any alignment marks or slots are matched correctly.
11) Before re-fitting the gearbox ensure that all the gearbox dowels are in place and that they are not excessively worn. Ensure that any dowel bolts are replaced in the correct location.
12) When offering the gearbox up to the engine take care not to damage the diaphragm fingers, release levers or release plate with the gearbox input shaft.
13) Ensure correct release bearing/clutch pedal adjustment, ensure correct pre-load with constant running types. Always re-set any self adjusting mechanisms that may be fitted.
14) Check the condition of engine and gearbox mountings, replace if necessary. Ensure there is no excessive backlash in the universal joints or the rear axle. Below: Gearbox mounting
15) Check the condition of hydraulic systems and replace any substandard parts.
16) Check the condition of the clutch cable and ensure that it has not stretched or frayed at any point. Replace any substandard parts.
Note: It is recommended that the clutch cables are replaced whenever clutch components are renewed.
Following these guidelines will help to ensure a trouble-free clutch replacement and optimise the lifetime of the new clutch and associated components.