There has to be some clearance! At least for your throwout bearing anyway. While plenty of things in your car should be bolted up tight and have no clearance or play, the throwout bearing is not one of them. In this video our buddy Mike Finnegan is showing you how to measure for proper throwout bearing adjustment using his American Powertrain Hydramax system. A hydraulic throwout bearing needs to be measured, and adjusted if needed, during installation. If there isn’t enough room between the throwout bearing and the fingers of the clutch then as the clutch wears it will hit the throwout bearing before it is completely engaged which can result in premature wear and clutch slip. If there is too much room then the throwout bearing can’t travel far enough to release the clutch and will either cause the bearing to overextend or will not allow the load to be released from the clutch which could make stopping or shifting harder or impossible.
There are simple spacers for adjusting the throwout bearing depth, so that part of the procedure is pretty simple. Measuring it is also simple, but causes confusion for a lot of folks. But it’s simple. Lay a straight edge across the opening at the transmission side of the bell housing when it is installed on the engine with the pressure plate in place. Measure the distance from the fingers to the straight edge. Write that number down. Now, measure from the mounting face of the transmission to the face of the throwout bearing that will come in contact with the fingers on the clutch. Write that number down. By subtracting the throwout bearing measurement from the bell housing measurement you should come up with the gap that is present. If that gap is .100 to .150 inch then you are good to go. If not, then some shimming may be required.