Does My Clutch Need A Shim?
****YOU ABSOLUTELY MUST MEASURE YOUR SETUP TO MAKE SURE THE TOLERANCES IN YOUR VEHICLE WILL NOT CAUSE RELEASE ISSUES OR POTENTIAL CLUTCH DAMAGE. IF YOU DAMAGE THINGS FROM NOT MEASURING IT WILL NOT BE COVERED UNDER OUR WARRANTY. IF YOU HAVE ANY QUESTIONS ON THIS PLEASE CONTACT US DIRECTLY.****
Never attempt to measure the setup with a tape measure, you must always use a set of calipers – whether they are digital or not does not matter, as long as you can read them. If you contact us with measurements, they must be to the .001” or we cannot help you.
Tick Performance sells shim kits HERE if you need them, additionally, we can make any thickness shim you can dream of, just contact us directly and we'll go over that. We like to see no less than a .0625" gap and no more than a .200" gap on our units, ideal is 0.085"-0.100". DO NOT TAKE OTHER PEOPLES INFORMATION AS WHAT'S CORRECT FOR OUR CLUTCHES, USE THESE TOLERANCES OR CONTACT US FOR FURTHER EXPLANATIONS.
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:
- 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.
- 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.
The diagram below will help you measure your installation. Further, anyone running an SFI approved bell housing will most definitely need a shim, this is due to the tolerances of these units manufacturing processes.