TECH TIPS – Evaluating Your Clutch Plates and Springs

Clutch Plates

When evaluating the clutch plates and springs, clean and inspect the clutch plates for obvious signs of damage or wear. When the inner tabs on the plain steel driven plates are showing burrs, they will fit on the clutch center splines loosely and will contribute to premature wear to the clutch center, leading to a dragging clutch.

Also check them for flatness to ensure they are not warped. If the tabs are not overly worn, and the plates are flat, they can often be refitted for service. A trick that has served me well over the years is to bead-blast the steel plates to remove the glaze that occurs during normal use. This will aid in adhesion to the friction plates during clutch engagement. The inspection of the locating tabs on the friction plates will also need to be done.

“A trick that has served me well over the years is to bead-blast the steel plates to remove the glaze that occurs during normal use.”

Another key measurement is one that is not mentioned in the factory workshop manuals. The stock driving clutch plate segments usually measure .155” thick (new), but will wear thin in service, leading to clutch slipping. When the thickness of the friction segments falls to .140”, it is good practice to replace the friction plates to obviate the need to compensate for the wear by overtightening the clutch springs, resulting in a heavier pull at the handlebar control lever.

Clutch Springs

One more important measurement in evaluating your clutch plates and springs is to make is the free length of the clutch springs. The clutch springs should be replaced when the measurement reveals that the springs are shortened by .100” or more. Clutch springs are relatively inexpensive and are asked to perform a critical function in the clutch assembly, so it is a false economy to put worn and shortened springs back into service when they have taken a set.

Check out our other blog: TECH TIP: How to Install New Clutch Rubbers