Is your manual transmission getting harder to shift? Does it feel like it just doesn’t grab like it used to, or maybe it’s starting to chatter or vibrate? Is your clutch slipping? A worn clutch may be the culprit here, or it could be the result of something else, such as a transmission misalignment. One obvious sign that misalignment is the problem would be rust residue on the disc and pressure plate.
Pinpoint the problem
In the case of the driveline shown to the right, one of the two transmission dowel pins was missing, which allowed the transmission to tilt down on the passenger side of the vehicle, causing the misalignment. The input shaft on the transmission was also heavily worn where it rides on the pilot bearing, due to the misalignment.
Correcting the cause of the problem was simply a matter of making a new dowel pin for the transmission and installing it. Although this relatively simple fix is just one example of many possible problems that might need to be addressed, the procedure for service and reassembly applies to clutches in general.
Mr Transmission Madison 