ok, so i have a new clutch master cylinder, and slave cylinder, and i have it bled properly. but for some reason, the clutch will still not release. when i try and start the car it lurches forward when its in gear, even if i have the clutch pedal pushed to the floor. and i can see the slave getting full extendion.

does anyone have any idea what the problem is? i have a new suspension setup i want to put on so i can get racing but i need to finish this first. my idea is that the pilot bearing is seized to the input shaft on the trans. what do you think?

 

Pilot bearing

 

PIlot bearing??? Explain that will you

 

its the bearing that sits inside the flywheel. and the input shaft goes into it....

 

Well, If the pilot bearing was really seized or chewed up, it could be turning the input shaft of the transmission, even if the clutch is dis-engaged.

Before I assumed it was the pilot bearing, I would make sure that the shift fork wasnt messed up or the clutch itself pooched.
In those cases however, the clutch would likely have a really weak, or unusual feel.

If the clutch FEELS normal, then the pilot bearing is a possibility.

 

well the clutch doesnt feel as strong as before, but like you said,it turns the input shaft even when the clutch is dis-engaged.

 

Have you had the transmission out, in that case you could have screwed up replacing the throw-out bearing.

It can only be in one position to work proberly.
I know cus it happend on my racecar, the bearing will need more travel to disengage the clutch.

 

i havent removed the trans yet... i dont have a jack.

 

The clutch fork rides on a pivot ball that is bolted inside of the bell housing, I have not only seen these wear down over time, they can snap off. The result being the clutch never fully disengages. If the pushrod on the slave is extending it's full length, the pivot ball is most likely the culprit.

 

Just because the clutch pedal is pushed down doesnt mean the clutch is dis-engaged. Enough chit chat, whatever it is if the hydraulics work but the clutch doesnt its gonna require you to drop the tranny! haha.

 

i also had this problem about a month ago, it turned out that the friction material on the clutch disc broke off and a chuncl had been lodged between the preasure plate and disc causing it not to be able to fully disengage

 

Had same issue with mine... same symptoms... this is what my tranny looked like when I dropped it. Pilot bearing death:

 

yea, i realize this. i just want some kind of idea what i will be looking for.

 

OH!!! if it helps. it went during my first lap at my autocross. so which would be more likely to fault during a race. the fork or the bearing?

 

It's like asking, What came first? The chicken or the egg?

Whatever has failed was on it's way out. Regardless if you drove it harder than normal.
The release bearing could of froze up and seized on the input shaft.

When you get it out then we will know what has happened.

 

Why? Genetic evolution states the egg came first, with anomalous DNA diverging it from proto-chicken. It then hatched, and grew into a chicken.

Meanwhile, his situation is he wants to know which was more likely to fail of the two. The answer is either one, all things considered, and he'll have to drop the tranny anyhow. Then know the culprit.

 

Did you bleed the slave?

 

i forgot that one time when i tried to start it with the clutch pushed and it did, and i could use the clutch. then it died and a few tries later it quit.

also it was acting as if the slave or master where going bad. it would go in and out. and only disengage a little.

oh and i cant push the fork with my hands.

yes i did.

 

extend the clutch pedal's push rod. Other than that, it time to get a new clutch.

 

why do you say that? the clutch itself is not slipping at all.

 

Hey Mate,

It sometimes necessary to extend/adjust the length of the clutch pedal's push rod located at the top of the pedal in the car where it pushes into the master cylinder through the firewall to get full extension on the slave and thus disengaging the clutch, usually when you have swapped to a "heavy duty" pressure plate set up.

It sounds like the clutch set up WAS working o.k. before, so I don't think your problem lies with the adjustment there.

You said that your slave cylinder is getting full extension? It may pay to unbolt the two bolts securing it to the car and just check that it extends and retracts the full way when it's not pushing against the top of the clutch fork.

If thats ok then the problem lies with either the fork itself or the pilot bearing.

The forks can sometimes snap (if your lucky) or just bend (right before they snap) and thus when you extend the slave cylinder the top half of the fork you can see outside the bell housing moves, but inside it does nothing and thus won't disengage your clutch.

Lastly the pilot bearing may have come away from the fork or died and need replacing, you won't know without dropping the gearbox out and checking.

Sorry Mate, long story short i'm pretty sure your gonna have to remove the gearbox and have a closer look...

Cam...

 

No, this was something that came on very suddenly. I doubt it has anything to do with adjustments. When it happened, it seemed like he just lost hydraulics. You were able to push the clutch in and get it into gear only at idle. If the rpms were up at all then it just wouldn't go into any gear. Felt like weak hydraulics just from sitting in the car.

You can move the fork with your hand, eh? Easily? I'd say you're gonna have to drop the tranny and replace something or other.

If you can find a way to get it over here on a weekend, I can give you a hand with it. I have a spare tranny and a (presumed) good clutch that I'm not doing anything with right now, just in case you end up needing something.

The rx7 community in this area has suddenly gotten very tight lately. Actually, just car enthusiasts in general. All of us meeting up and getting to know each other. When I swapped out my rear end last week, I had like a dozen people show up to help, just because they heard what was happing through friends. It felt pretty awesome, to have that kind of support.

So anyway, if you can get her over here there is no doubt that we'll get you rolling again. I think it's like twenty bucks or so to rent a car dolley, if you have something to pull it with. Otherwise, Uhaul rents trucks that you can carry a car on. Just let me know if you can do it, and I'll get things set up over here.

 

no i cannot move the fork with my hands, thats why i dont believe it is the culprit. and i plan on removing it tomorrow, and i have a spare trans. actually i have like 3. so you have a new rearend? hope you didnt pay for it, cause i still got that lsd if you wanted it!

ill definitely bring my car over to do my suspension and steering though. so we can put on my coil-overs and my tokicos, and maybe ajdust that steering. good to hear from ya!

 

what the hell i just bumped this and it didnt go to the top. BUMP goddammit.

 

lol. Yeah, I'd definitely give you a hand with that suspension. The lsd swap came all of a sudden due to a bad wheel bearing. Got a good deal on a really nice unit though. And steering adjustment I can certainly do (time to give mine a little tweak again anyway)...