Does My Clutch Need A Shim?

During your next clutch install, determine if your slave cylinder needs to be shimmed or not. To do so, you need to take two measurements:

1. Measurement “A” is the distance between the surface of the bell housing that meets the transmission to the tip of the pressure plate fingers. To get an accurate measurement, the clutch must be torqued properly.
2. Measurement “B” is the distance between the release bearing surface to the transmission surface that meets the bell housing. To get an accurate measurement, the slave spring must be removed and the bearing must be fully seated at the bottom of its travel; resting on the slave’s base.

Once you’ve got your two measurements, make sure that measurement “B” is LESS than measurement “A”. If you come up with more than .200″, add an appropriately sized shim between the slave and the transmission in order to get the measurements where they need to be.

If there is no difference between the two measurements, or if “B” is greater than “A”, there could be a problem with clutch engagement which could result in premature clutch slip and eventually a total failure – if you’re getting a “positive gap” remove the bleeder completely and make sure the slave cylinder is fully compressed and remeasure – it’s not uncommon for slave cylinders to get air trapped in them and cause false measurements. If after this the measurement is still as it was then reach out to us immediately.