To start off, my car has new transmission fluid, new diff fluid, new master and a new slave cylinder. The clutch line is the OEM, rubber one.

The issue I am having is shifting into gear. This happens after the car has been running for a while and gets 'hot.' A side effect is the transmission bay gets scorching hot.

When in this situation, when I try to shift gears from a stand-still, it is almost not possible. Or I try to shift it into gear and I hear grinding. I also cannot shift into reverse unless I turn the car off first, put it into gear (no problem when the car is off) and turn the car on.

Again, if I let my car sit and cool down, the shifting comes back to normal. Also, I think a workaround I found yesterday when driving is if I press the clutch pedal a few times before attempting to shift, I don't have any issues shifting.

This all only happens when the car is warm/hot and from a stand-still.

Thoughts?

 

Is the clutch pedal throw well adjusted and the hydraulics have been adequately bled? There are a couple of things there:
- scorching hot floor over the trans points to a catalytic converter problem, unrelated to the trans. See if you see red glow under the car when it's scorching hot.

- having to pump the pedal to get proper clutch action means your hydraulics have a leak or an air bubble. I'd say a leak, because a bubble alone would rebound with each press, but a leak usually creates a bubble. So..

What was the reason for the slave and master cylinder change?

 

I'll check the cat next time this happens - didn't even think about that.

Bleeding should have been fine when I changed out the fluid, Also the clutch feel is the exact same when cold (no problems) and when it gets hot (with problems). I also don't see any fluid under the car.

I don't remember my reasoning for changing the master/slave. I believe the slave failed and I changed both at the time.

 

Changed out the cat; I had a BHR midpipe and talked to Charles and got a high-flow cat. Went to a shop and they welded it all together and installed it (only cost me $100 which was great to hear).

Center console is a lot cooler - back to normal "keeping drinks luke-warm" temperatures. Still wish there was a way to stop the RX-8 from doing that...

Anyways, back to shifting - still problems. But, I have been testing my theory of pumping the clutch a few times before shifting. As I drove the car more (it got hotter) I had to pump more in order for me to be able to shift into first/a gear.

When it started happening, I would pump a few times and it would work. This makes me really think it's the shitty, OEM rubber clutch line that is losing compression and causing the hard shifts. Could this be a potential culprit?

I am going to double check my trans/diff fuel levels just to make sure.

 

It sounds like the clutch isn't completely disengaging. It's possible that the clutch line is ballooning and it's worse when hot. On the bright side, a new stainless braided clutch line is ~$40 on Amazon so it's not an expensive hypothesis to test.

That said, before I tried replacing a part, I'd try bleeding the clutch hydraulics one more time, just to be sure.

 

That's fair. And I agree, I'd rather try bleeding, then replacing the clutch line first - before I rule out a bad clutch/transmission

 

From your description, it does not sound like the transmission itself has a problem. It sounds like the hydraulic system. Replace the clutch line (a $5 rubber one is fine) and search for some different bleeding methods. It can be very difficult to fully bleed a new master.

 

I am going to try that this weekend. Make sure my tranny is topped off with fluid - it should be. And double check lines are bled properly and the clutch line isn't ****.

Then I am going to probably have to look for a new tranny. I am happy, looking line, that they aren't too expensive. I almost was on the verge of figuring out how to sell the 8 and look at something different :'(

 

You aren't allowed to buy this out from under me...
https://chicago.craigslist.org/chc/p...630932182.html

2nd gear synchro isn't happy in my gearbox (and 3rd isn't far behind) and I'm planning on replacing it myself. In the mean time, I'm going to see if that one will work so I don't have to park my car for months while I figure out how to open and replace **** inside a transmission.

I'm going to pick it up late Saturday morning, swap mine out Saturday afternoon and then autocross it as a stress test on Sunday. If you beat me to it, well... screw you, buddy. If not, I'll see if they have any others in inventory and let you know if it's worth a damn.

 

Sounds good. Damn rain stopped me from doing a bunch of the things I wanted to do. The new clutch line is coming in and going to bleed the system again when that does. Does anyone have suggestions for what type of High Temp brake fluid to use?

I added a bit more transmission fluid through the shifter hole and that seemed to help out a bit. Got another bottle of MT-90 coming in from Amazon, going to put maybe another 1/4 qt in there to see if it doesn't produce better shifting results.

 

Hey guys just thought I'd chime in here, my 8 was having the exact same issue as described, but I could see the fork actuating so I was hesitant to chalk it up to the hydraulics. Anyways long story short, I decided to drop the tranny and take a look. What I found was a finger on the pressure plate had broken off and wedged itself in between the friction disc and pressure plate.

http://imgur.com/a/XXsWh8k

I can't describe why the issue only occurred when it was hot but mine did show that same symptom (must've just happened to coincide with when the broken finger was jammed). Although after taking the car out a couple times it reached a point where it would no longer disengage at all. I'm in the process of reinstalling everything (had a few broken bolts along the way ), i'll update when everything is back together.

 

 

Instead of cluttering up an existing thread with unrelated information, start your own thread here.