My wife loves her RX models. Her first car was a first gen RX-7. Before I met her she had a '93. When we were dating she had an '04. Last year she purchased an '05 Shinka. I've been a mechanic, in one form or another, most of my life. I've done minor repairs to RX models in the past. Now it's like learning a whole new automotive language... no problem.
We picked up Susan's RX-8 last summer. The '05 Shinka was showing 90k miles with documentation of a factory replaced engine at 60K miles. Car ran great but it had an ever so slight rattling noise when the clutch pedal was depressed. It concerned me but didn't seem to affect the drivability. We put maybe 3k miles on the car last year when out of the blue the clutch wouldn't engage (disconnecting the engine from transmission). It acted as if the clutch master or slave cylinder was not performing properly. The car is well taken care of and not driven hard in the time we've owned it. I limped it home taking many precautions to not get stuck at stop signs or lights. By the time I got it in the driveway, pressing on the clutch pedal became completely useless. There was plenty of pressure/resistance on the pedal when pushed, it just didn't seem to operate the clutch assembly.
I was slightly confused as to how quickly the issue took place. My first thoughts were:
Clutch master or slave cylinder quit working or a leak developed.
Clutch pedal or push rod came out of adjustment or broke.
Clutch pedal bracket assembly fatigued/broke (although pedal still felt fine).
Clutch disc burst and debris was binding the pressure plate to the flywheel.
Pressure plate grenade'd and wasn't releasing when actuated.
Clutch fork bent or broke.
I also noticed DSC and Traction control lights lit up on the dash. Talk about trying to confuse a guy.
I put the car on jack stands and began diagnosing. No leakage at the master or slave. Clutch fork appeared to have sufficient travel. Pedal assembly in good working order and operation. Removed the starter looking for signs of ruptured clutch disc but all looked good. Time to pull the transmission. Once I dropped the exhaust and the torque bar (not sure of the proper term) between the trans and diff I had access to complete the removal of the transmission. All seemed to be going well until... trying to separate the transmission from the engine. It wouldn't budge. It took about an hour or mild pulling, prying and multiple checking (making sure I had everything disconnected) before the transmission came loose. Appeared as if the pilot bearing seized up and was trying to weld itself between the eccentric shaft and the input shaft of the transmission.
After careful inspection I came to the conclusion the bonehead that installed the engine 30k miles prior did not grease the pilot bearing before mating the engine to the transmission. Only reason the bearing didn't fail sooner is because the engine and trans are locked together except when at stop lights/signs when the clutch pedal is depressed.
It took awhile to get this job done as I was working on the car outdoors and the weather wasn't always agreeing. I did manage to have a little floor space in our garage to work on the transmission. The eccentric shaft was not damaged (thankfully) but the input shaft wasn't so lucky. I tried to clean it up with emery cloth but couldn't get all the pitting out to my satisfaction. We aren't planning on getting rid of the car and I want the work done correctly. I researched new transmissions and junk yard transmissions. I settled on repairing the transmission that was in the car as it worked well before the pilot bearing deteriorated. I ordered a new input shaft as well as an Exedy complete clutch kit and I began transmission disassembly.
I post this info as one of the few possibilities to some of the clutch issues associated with the RX-8 (e.g. pedal bracket failure, master/slave/line failures, clutch disc or pressure plate failures).
As for the car still pulling itself when the pedal was depressed, I'm sure there are those that would argue it's not possible for a car to move just from the locking of the pilot bearing while the clutch is being disengaged (pedal pushed in). I beg to differ.
The new input shaft went in with some work. Transmission was installed with the new clutch assembly. Everything seemed to fall back together much easier than coming apart. While the car was on jack stands I even installed new drilled and slotted rotors and brake pads along with wire brushing and painting the calipers and mounting brackets. As for the warning lights on the dash I figured it had something to do with transmission not disengaging. Once the car was on the ground and warmed up I took it for a drive and the warning lights went out rather quickly. We've put about 3k miles on the car since the repair with no transmission or clutch issues.
I'm obviously new to this forum (why I'm posting in the New Member Forum) and this is my first post. I read some other threads pertaining to clutch issues but didn't find one that was definitive to the pilot bearing same as the issue I had, although it had been mentioned.
Everybody likes photos and I thought a visual might help the readers.
Susan's fourth RX she's owned.
What's left of the pilot bearing and the seal.
Input shaft after trying to clean up the pilot bearing riding surface.
Couldn't bring myself to chancing it and reusing it.
I need a workbench.
After installation of the new input shaft. I wouldn't suggest a novice or intermediate mechanic attempt this. Too many things that can go wrong.
The old clutch assembly. Not only the lining is looking pretty worn but the springs in the disc were loose. I believe that's what was rattling when the pedal was depressed when we first got the car. Notice the hot spots in the pressure plate? We had a clutch chatter also. New clutch took care of that.
