To replace the clutch in a Miata--or any car for that matter--the car must be raised and supported securely on jack stands for safety. It also must be high enough to afford working room underneath. The clutch life span is in most part reliant on the driver's habits and type of driving. Keeping ones foot on the clutch pedal or holding the car on a hill with the clutch pedal will most assuredly accelerate the wear and dramatically reduce its service life. Drag racing and hard accelerations actually have less effect if the clutch is rapidly engaged as opposed to slipping the clutch. Replacing a clutch requires a certain amount of mechanical aptitude, and is not recommended for beginners.
Remove the plate holding the leather boot on the gearshift arm. Make sure the car is in neutral with the rear wheels blocked (do not pull the emergency brake), and remove the bolts holding the gearshift into the top of the transmission. Lift the gear shift handle straight up and don't move the round cup inside that the ball end of the gearshift rides in when installed. This will keep the transmission In neutral and make it easier to install.
Raise the Miata for sufficient room to work underneath and support with jack stands.
Remove the bolts on the rear yoke and remove the driveshaft. Place a bucket under the Miata's rear tailhousing of the transmission to catch any gear oil leakage.
Remove all electrical connectors from transmission. Remove the bolts from the rear transmission mount. Place the floor jack under the transmission and raise it just enough to take weight off trans mount. Remove bolts in cross member. Remove the cross member and set it aside.
Remove Miata's flywheel front cover bolts and the cover. Remove all the bolts except one bottom bolt from the trans housing to engine. Remove the slave cylinder. Using a wire tie, hang it out of the way. Make sure the transmission is supported well by the floor jack and remove the last bottom bolt.
Pull the transmission back with a little wiggle to either side to break it loose, lower it and move it out of the way as much as possible. Using the 3/8-inch air impact gun, remove the bolts to the pressure plate. Keep a hand on the pressure plate so it does not hit you on the head, since it is awkward and a little heavy. Remove the pressure plate with the clutch plate at the same time.
Install the new Miata clutch using the clutch centering tool and make sure that the right side of the clutch is facing the flywheel. The highest side of the center of the clutch always goes toward the rear of the car. While the clutch is being held in place with the installation tool, install the pressure plate over top of the clutch and make sure the dowel pins on the pressure plate are located in the corresponding holes of the flywheel. Insert the bolts loosely. Make sure the centering tool is in straight and the clutch is aligned in the center of the pressure plate. You can tell easily by looking at the outside circumference of the clutch and pressure plate and make sure there is no overhang. Tighten the pressure plate bolt down. Withdraw the centering tool.
Install the new throw-out bearing in the fork arm of the transmission. Watch how the springs are located that hold the old throw-out bearing in and put the new bearing in the same way. Bring the transmission back up to the right position and lift it up to reinsert it into the flywheel. Carefully line up the input shaft to the hole in the flywheel and push the transmission in. Install the bolts in the housing.
Raise the transmission up enough the get the crossmember under it and install the bolts in the crossmember. Lower the transmission onto the crossmember and install the transmission mount bolts.
Install the clutch slave cylinder and tighten the bolts. Reconnect all the electrical connectors. Install the Miata's drive shaft and tighten bolts on the rear yoke. Install the gear shift handle into the round cup, which should be centered in its cavity in the transmission, and tighten the plate to hold it down. Install the leather boot and screws.
