The following procedure outlines what adjustments and clearances must be set to ensure the ideal clutch setup, longevity, and avoid common costly mistakes.
Whilst clutch design has not evolved a great deal over the past few decades, the surrounding mechanical components have. With these changes one would believe that clutch setup can vary dependent on the type of componentry installed in a vehicle. However clutch installation and maintenance is still very true today as it was two decades ago.
NOTE: When replacing the clutch in a vehicle there are several critical measurements that need to be set for correct operation on an Eaton Advantage Series Clutch.
Before adjusting any linkages, hydraulic slave cylinders etc. we begin with looking at the set up only of the clutch for correct operation. To do this, we must ensure we conduct the following checks:
- Checking the flywheel to be within manufacturers specification after machining dimensions. You will need o check flywheel run out for
- Flywheel face
- Flywheel spigot bearing bore
- Flywheel housing
- Always when mounting the clutch to the flywheel ensure you are using appropriate equipment (the transmission input shaft should never be used as the aligning/installation tool. The input shaft bearing is not designed to support clutch weight and premature damage to input bearing can occur.
- Modern genuine clutches do not use separator pins on the intermediate plate and are now commonly ‘strap driven’. Eaton Advantage Self-Adjust and Easy-Pedal range no longer require roll pins to be tapped in. Doing so may cause uneven clutch wear, hang-up, or slipping.
- Once the clutch is mounted and fasteners torqued in correct sequence then the transmission can now be installed. It is advised not to lubricate the input shaft of transmission (the input shaft splines need to be kept free of grease and anti-seize).
Once the transmission is installed the set-up procedure of the clutch is followed, which depending on type (SelfAdjusting or Easy Pedal) is out lined below.
- For Mechanical linkage: confirm all joints are in serviceable condition and adjust to remove all free play. For hydraulic, go to step 2.
- Press clutch pedal five times to the floor ensuring you contact the clutch brake on each application.
- The gap between release bearing (RB) and clutch brake (CB) should now be set between 12.7 -14.22 mm and clutch wear indicator will have moved from new position.
- Now we can set CB squeeze. Have an assistant place a 0.25mm feeler gauge between RB and CB, and depress clutch pedal to the floor. Then slowly release, taking note when the feeler gauge can be removed (This should be no more than 25.4mm). If it is greater than 25.4mm use free-play adjustment to increase free-play within the following range (RB to clutch fork/yoke clearance needs to be set to between 1.6 – 3.2mm).
Eaton Advantage Easy Pedal
- The set-up dimensions for the Easy-Pedal are similar to the Advantage Self-Adjust, the only difference is that you set the RB-CB measurement via the quick adjust nut.
- The RB to CB measurement needs to be set to the higher side of the recommended range (12.7-14.2mm) and set to 13.70mm- 14.00 mm of the range as the intermediate plate is spring separated now.
NOTE: The ‘old’ half inch is the minimum which when a floating intermediate plate was in use would suffice, however with the modern spring separated intermediate plate, if the clutch doesn’t open sufficiently then there can be pressure applied by the intermediate plate to the front driven disc to flywheel, the result is that drive can’t be broken and a driver’s response is that he has trouble disengaging gear.
- When you have set the RB to CB clearance (13.70 -14.00mm) you now need to set the free play on the clutch fork (yoke) to release bearing wear pads 3.2mm.
- Once RB to CB and free-play have been set then you need to verify clutch brake squeeze – The same procedure as a Self-Adjust clutch.
Have an assistant insert a feeler gauge between the RB and CB and depress the clutch pedal to the floor. Slowly release pedal taking note of when feeler gauge comes free (this should be a at 25.4mm from the floor). If this isn’t achieved DO NOT move the RB closer to CB to achieve clutch brake squeeze as this will reduce driven plate separation clearances and drive hang-up will occur.