The idea for our NA/NB Miata hydraulic release bearing was born out of necessity. The stock Miata slave cylinder interfered with the 3 inch downpipe from our K24Z3 swap that runs along the right side of the transmission. This part was our solution to delete the stock slave, clutch fork, and release bearing and provide the necessary exhaust clearance. However, other benefits were immediately apparent:
-The factory slave cylinder is eliminated
-Less pedal effort is required to operate heavy duty clutches
-A more linear clutch engagement is achieved over the stock system
-K24A2 swapped cars eliminate the slave cylinder near the exhaust that can cause clutch fluid overheating in hot endurance racing environments
This product was designed in partnership with Quarter Master and is based on their 740 series release bearing.
This kit includes the bearing, piston, housing, new hardware, new gasket (5-speed only), new Mazda seal, and a clutch bleeder and line.
Important Installation Notes:
1) This bearing must be paired with any 3/4" master cylinder, like the Wilwood kit available here. The factory Miata 5/8" does not move enough fluid to provide full clutch engagement.
2) We now only recommend pairing this bearing to the Exedy Stage 1 clutch. Exedy holds extremely tight tolerances for pressure plate height, which is important for reliable operation of this unit.