The clutch is a critical component in the operation of manual transmission vehicles. The clutch allows the transmission to disengage from the engine, allowing the operator to change gears.
To work correctly, the clutch needs the right amount of freeplay in the linkage between the foot pedal and the clutch operating lever. If the amount of freeplay or clearance is low, it results in a slipping clutch. If there is too much freeplay, the clutch may be dragging.
Over time the clutch wears down and requires adjustments. The clutch freeplay must checked and adjusted at every 6,000 miles or as specified in the maker's service schedule.
Newer vehicles use a hydraulic clutch and slave cylinder that are self adjusting and do not require adjustments. Older vehicles use a clutch cable and clutch lever that require adjustments at regular service intervals to keep the clutch wearing evenly and in good working condition.
- Warning: Improper clutch adjustment can cause the clutch to slip or uneven wearing of the clutch. Ensure that you follow the manufacturer's specifications while adjusting the clutch and refer to the owner’s manual of your vehicle for the right process.
Part 1 of 3: Measure Clutch Pedal Freeplay
The first step in adjusting a clutch is to check the clutch pedal freeplay. This measurement will give you a baseline to go back to and you can then adjust the clutch pedal free play to fall in the manufacturer's specification range for your vehicle.
Step 1: Measure the clutch position. Set a block of wood down next to the clutch pedal. Mark the height of the clutch pedal without depressing it at all.
Step 2: Press the clutch and measure its position. Press the clutch pedal several times. Mark the height of the clutch pedal at the location where you feel the clutch engage.
- Note: You will need another person to depress the clutch pedal for you so that you can get an accurate measurement.
Step 3: Determine clutch pedal freeplay. Now that you have a measurement of the clutch pedal height when it is disengaged and engaged, you can use the measurements to determine the freeplay.
Calculate the freeplay by determining the difference between the two numbers obtained earlier. Once you know the freeplay, compare the number to the vehicles freeplay specifications given by the manufacturer.
Part 2 of 3: Adjust the Clutch Cable
Step 1: Locate the clutch lever and the adjustment locations on the clutch cable. Depending on the vehicle, you may need to remove parts such as the battery and airbox to gain access to the clutch cable.
Most vehicles will have a locknut and an adjuster nut. The first step is to loosen the locknut and adjuster nut slightly.
Next pull up on the clutch cable and make sure the locknut and adjuster can be turned by hand.
Step 2: Adjust the clutch lever. Now that the adjustment nut and locknut are loose, pull up on the clutch cable again.
You will feel a point where the clutch lever engages. This is where the clutch cable should be adjusted too.
While keeping constant pressure on the clutch cable, place the locknut and adjuster so the clutch lever engages fully and smoothly without have any overtravel. This may take a few attempts to get the adjustment just right.
Tighten the clutch cable locknut and adjuster in place once you are happy with the placement.
Part 3 of 3: Check clutch pedal freeplay
Step 1: Check the freeplay after adjustment. After the clutch cable has been adjusted, get back into the car to check the clutch feel and free play measurement again.
Depress the clutch several times and check the feel of the pedal. The clutch should engage smoothly. This will also seat the clutch cable fully after a few depressions.
Now measure the clutch pedal freeplay as outlined in part one. The free play should be within manufacturer’s range specifications now. If it is not within specifications, you will need to adjust the cable again.
Step 2: Reinstall any parts removed. Put back any parts that were removed to gain access to the clutch cable.
Take the vehicle on a test drive once repairs are completed, to check for proper operation of the vehicle. Now that you have adjusted your clutch pedal, you can enjoy the smooth clutch while driving.
If you are uncomfortable performing the clutch adjustment process on your own, contact a YourMechanic professional for assistance with the clutch adjustment.