Manual transmission - clutch hard to disengage
 

I performed the slave cylinder recall last year as I was grinding going into 4th gear This is just at the track after the car warmed up. Street driving was fine.
I don't speed shift the car btw.
Anyhow this season it came back. Only the 4th gear crunching after a few hot laps.
Had my mechanic rebuild both slave and master before going back to Summit Point.
New AmsOil in the box so I am good to go.
No such luck. Same 4th gear crunch!
This is getting annoying as I typically stop driving the car at the event and take it home. Trying to minimize abuse as much as possible. Shortening three track events for me is tough to take.
So I guess if it was not the 4th gear syncro before it is now.
Bought a new S2 trans from Mazda comp.
I will put it in over the winter.
Still concerned about the hydraulics though.
I have a SS clutch line and use a speed bleeder.
I got a light wt flywheel Stage 2 clutch, AF shifter.
Always shifted nicely otherwise
Symptoms sounds very much like the recall notice.
Anyone else experience these problems?

I don't know why this would be hydraulics. Those would affect every gear.

Synchro, yep.

Thanks for the feedback Loki
That is what I would think, but a bad 4th gear syncro only when it heats up?
Possible I guess due to expansion.

i think you will find when you pull the transmission that the output shaft sleeve is all gummed up. it is what the throw out bearing rides on..

i went through this a few years ago.. replaced the same stuff you did.

bad news is pulling transmission is only way to get to it.

all this is assuming that you have checked you clutch pedal bracket.

good luck.

beers :beer:

Thanks swoope,
I did reinforce my clutch pedal before I installed the stage 2 clutch.
Piicked up a new SK T'bearing
Just waiting on the AF shifter to get here from UK.

Are you sure the clutch pedal is not adjusted too close to the floor. Not having enough pedal throw will cause the clutch to not open fully. Have seen it happen and similar to your sutuation. The shaft between the pedal and clutch master also needs to be checked/adjusted to make sure the clearance play is correct. Some people think the RX8 clutch pedal is too high and try to acjust it down without realizing what they are causing. It should also all be reset anytime you change the clutch etc. as well.

Cluthch
 

I had a lot of troubles with 2008 RX8. I tried pedal reinforcement. I replaced the clutch. I even upgraded, for other reasons, to the Gen2 transmission. That transmission is actually the Miata competition trans and is about twice the transmission than the Gen1/RX8 trans. Its not worth rebuilding the Gen1 trans. I also changed to a stainless steel hose and to a new slave cylinder. New throw out bearing and clean sleeve. Still had troubles like you describe with hard shifting. The trans replacement did resolve the fourth gear grind after the trans swap but hard shifting continued for sure. I found two things that resolved this. 1 even a turn or two either way off on clutch adjustment caused hared shifting. As said above by someone else the clutch adjustment has no tolerance for being wrong. I have a feeling the pedal reinforcement I put in changed the geometry and made the adjuster even more sensitive. The other thing that I found that helped a lot was power flushing the fluid from the slave cylinder instead of more typical flushing procedures. Oh, one other thing I found was that when at the track for high performance driving events that the sustained heat around the slave cylinder was prematurely deteriorating the fluid. This would lead to hard shifting when warm. Even though I use high temp race fluid. Very frequent flushing helped. I also added a cooling duct from the front "grill" to the slave cylinder helped a lot.


I also have found out in my BRZ that when I switched to Amsoil the 4th gear synchro started to grind. Went back to Subaru trans special oil and bam grinding gone. Subaru service tech foreman said he had seen that before and oil that is too slippery isn't necessarily best for synchros. They need to grab between sleeves as that is the purpose. I use Amsoil in RX8 gen2 trans no problem so it seems it depends on condition and on make and model of trans.


I can't recommend the Gen 2 trans over the Gen 1 transmission. Night and day.


Hopefully you can get the hard shifting resolved with some of my experience above, if you haven't already fixed it.

I've never used Amsoil trans fluid, but have great success with Ford Motorcraft XT-M5-QS, which I can pickup locally.

Never had any fluid/heat issues ...

Hello,
I'm having similar issues:
Very cold day, drove car for 5 mins all fine. after 3-4 gear changes clutch would not disengage to go into gear from neutral. tried following day, 1-2 gear changes ok, then again - wont go into gear unless I force/grind it (once in gear seems fine)- needless to say I parked it to save the tranny. pedal may be soft, (but im not sure if its just me being ultra sensitive now).

Thanks for any help.

FYI: brought it to the mechanic today (dealer) who test drove and called me to say it needs a new clutch and master cylinder. Doesn't really make sense to me, but I agreed to the master cylinder as that would mean they would replace the fluid.... If it needs a clutch then it needs a clutch.. just doesn't make sense to me with these symptoms.

2007 rx8 gt manual 90000 mi.

Before you go replacing parts at great inconvenience and expense I strongly suggest you check your clutch pedal adjustment. It needs to be adjusted quite exactly, not approximately, it will make a big difference. After that then proper flush not just bleed of brake/clutch fluid. Then I would start deduction process about clutch, pressure plate, throw out collar bushing, slave cylinder or master cylinder. But that is an expensive route to go when your problem may just be the clutch pedal adjustment or a real good entire flush of the brake fluid which is integrated with the clutch. Stupid question but check manual transmission fluid, if a fill or drain plug wasn't torqued right it can back out and resulting with oil loss. Check the simple stuff before the difficult and expensive stuff. Keep us updated.

sounds to me like they're going to take you for a ride down empty your wallet lane.

x2

beers :beer: