Good day all, I am having problems with a clutch recently installed in an '89 rx7 convertible. New clutch, pressure plate and throwout bearing. Slave and clutch master have been bled in both directions and have less then 3,000 miles on them. Slave rod lines up perfectly with the clutch fork, i even welded a small extension onto the slave rod to try to get a bit more travel into the throwout bearing. I installed a new hose to the slave as well. I never removed the clutch fork when i had the trans out so im confident its pivoting correctly. New pilot bearing, new pilot seal. The vehicle will not go into gear when its on the ground and running, but will when the rear tires are off the ground. I realize that this topic has been covered much on here, but im still scratching my head. The kicker is, even though i knew i installed the disc correctly, i decided to pull the trans today to make sure, and of course i was right. Installed the correct direction. Also, the flywheel was cut (both the face and mounting pads evenly) although Im not sure how much (calling the machine shop tomorrow). Car was driven to my place and clutch seemed ok, but the rear main was leaking so a swap was in order. Anybodys 2 cents are more then welcome.
Thanks all.

 

That's a whole lot of info for one paragraph. That being said, can you switch gears without engine on?

 

Yes car goes into gear fine while engine is off. It displays all the characteristics of a bad pilot bushing or reverse clutch disc install or bad clutch master or air in slave cylinder but all checks ok. After some investigation last night i found that there are 2 different part numbers for clutches on most part store websites for convertibles and coupes. This car is a 'vert and i believe the clutch kit was for a non convertible. Not sure what the difference would be yet. Im going to check the diameter of the original and compare with the new unit today.

 

All NA FCs use a 225 mm OD clutch disc (Turbo uses 240 mm OD clutch disc). There are 2 variations of stock clutch assemblies for the NA FC. The S4 stock clutch has a rubber sprung hub and the S5 has a spring hub. An S4 clutch assemble will work in an S5 and vice versa. I've used an S4 clutch kit in my S5 a couple times. A stock S5 clutch will give you a smoother launch due to the spring hub. An S4 pressure plate is centered on the flywheel using the 2 shoulder bolts, which are slightly longer than the remaining 4 bolts. The S5 pressure plate is centered on the flywheel using dowel pins, which are pressed into the flywheel. There are no differences between NA FC coupe and convertible clutches.

 

Thanks for the knowledge Hot Dog. I set the old and new discs side by side on the work bench for a comparison, and there seems to be a bit more "offset" with the new clutch. This is my first mazda clutch install, and I dont normally work on stick shift cars, so does this look normal to anybody? The clutch kit part number is KF714-01,which i believe was purchased from Rock Auto and is also listed on Orielly's website. It does state on Oriellys site that this part number will not fit an '89 RX7 Convertible (which im not sure why). Rockauto has it listed as a good unit for my application.

 

Your old clutch disc is very much worn out and hence the difference in thickness. The thicker new disc is not an issue here. As long as the discs are the same diameter and have same number of splines as the original than they are ok.

 

Ok yeah thats what i was thinking. The difference is a bit exagerrated by the fact that the discs arent both resting on the spline hubs. The springs in the original unit are fatter so its holding the disc up higher. So my last option is to reinstall the clutch kit and replace the slave and clutch master since i havent yet, even though they seemed to bleed out ok. I even pinched the new hose briefly while pressing the clutch pedal and it seemed to build good pressure so im thinking the clutch master isnt bypassing internally, and if it is its barely doing so. Ive included another pic of the discs, this time both are sitting on their respective trans side spline hubs. As you can see the the flywheel sides seemed to be closer in position, but the trans side is obviously different. Even the center of the discs are off by .125.

 

I've had a number of bad experiences with Rockauto selling me parts that were mis-boxed (i.e., wrong part in box with correct p/n). You might want to recheck those parts.

 

Yeah Im going to try and take both discs to a good friend of mine who is a transmission specialists and get his thoughts. From doing some searching online it looks very similar to an Exedy stage 1 clutch kit. Im not sure if the pressure plate design is the same across the board on the 1.3 motors or not. Maybe the disc and pressure plate dont jive? Im not reinstalling this thing till i get some verification. Thanks for following up with me Hot Dog.

 

Maybe try contacting Exedy Tech Support at https://www.exedyusa.com/tech-support-faqs/.

 

I think I may call them. Im sure they could help get all my ducks in order.