Transmission issues
 

So this is a problem thats been progressively getting worse since I got my car. Even with the clutch fully pressed the car judders when I push it into gear, so I assumed maybe the thrust bearing was toast as I can hear a bearing making noise under the car with the clutch up. The next thing I noticed was at high RPM sometimes it won't go into gear, just grinds. So I though again, maybe the clutch isn't fully disengaging which would explain it. But after a hooning session today it really struggles to get into gears at high RPM and now its getting stuck in reverse. I was on my way home and was reversing back and it just wouldn't get go of reverse. I sat that for a good 10 seconds pushing at the shifter before it let go. So I drove it on again and went to parallel park and again stuck in reverse. So is my tranny fucked or is this still a clutch assembly/clutch related issue? Thanks!

have you checked the clutch bracket?
there's a weak weld that can crack and inhibit the ability for the clutch to fully engage causing shifting issues.

I have heard the clutch bracket can be bad. But a symptom of that is lateral movement of the pedal. My pedal only has a tiny bit of side to side play so I just assumed it was okay. I'll look up a video on the cracked weld and see if I can spot it in my car. Thanks

Not sure if it was you or someone else, so if you already tried this, ignore me:

hold clutch in, car in first, stopped on level surface. Does the car creep forward?

clutch in, car in 5th, stopped on level surface: do the rpm drop significantly compared to idle in neutral?

If you sais yes to either of the above, you may have a pedal out of adjustment, so it's not disengaging fully. There are 2 nuts on the clutch pedal pushrod. If you adjust them toward the rear of the car, the clutch will disengage earlier in the pedal travel. If the nuts are set too far forward, the clutch is never fully disengaging. I may have that backwards. Play with those and see.

I'll try these things tomorrow. However i've been on a few flats since this started happening and I can't say I noticed it, granted I wasn't specifically looking for it at the time. The fact I can hear a bearing under the car with the clutch up probably means something in the clutch assembly is fucked. I'm thinking throwout bearing.

If I can't diagnose the issue myself i'll take it to my mechanic and he might be able to figure it out. He has experience working on 8's, usually de-flooding them he says haha

Check the clutch master and slave cylinder for leakage. Look inside the cab below the clutch master cylinder for for fluid running down the firewall. If their not leaking I would bleed the clutch system.

There is not much to be gained by adjusting the clutch master's actuation rod, it is more of an initial setup adjustment. There needs to be some clearance.

^ I agree. The clutch should not need to be adjusted after setting it initially.


Bearing noise is pretty common among 8s (any Miatas and MX-5s). Mine has it. It can be completely benign.


Have you peered into the clutch inspection hole in the tranny?

I didn't even know there was an inspection hole haha. I can't work on the underside of my car really as there isn't anywhere flat near me, and my trolley jack is broken. If it is a clutch issue i'll have my mechanic look into it. My old MX-5 did make bearing noise under the car but I don't remember it being quite as loud as on my 8.

In reply to Loki, I tested the movement on flat earlier and the car doesn't move, neither does it bog down in 5th gear. But as I said with the clutch fully pressed to the floor, pushing the car into gear causes a jolt and that bogs the RPM a fair bit.

In reply to Leo i'll check the cylinder for leakage later. I as I understand it the slave is on top of the transmission so I doubt I can get up there. But I can sure check the master. The clutch still works good despite having this issue so it can't be leaking that badly.

Thanks for your replies everyone. I hope to get this issue sorted soon.


EDIT: I just checked and there is no leaks from what I can see. I checked pedal movement again and there is little side to side movement, no more than the brake pedal. And I sat there for 3 minutes while it was warming up playing with the gears and I heard something move and reverse seems to release normally now. I'm thinking the high RPM gear grinding that happens sometimes might have thrown some metal and got stuck into the reverse gear. Whatever it was its cleared now. But I still have the original problem of high RPM grind in most gears. 3,4,5 especially. It usually lets me into 6th no problem. 3rd is usually okay if I give it a good shove. I'm going to take my car to my mechanic next week to see what he thinks.