I'm at a loss, all I am going to say is this car is lucky I love it so much, if it was any other car it would be on the express truck to the crusher.
You probably remember me and this car from previous posts regarding faulty slaves and flywheel spacers. Same car. 1984, 4 Speed Muncie.
Clutch has been good for 5k miles. One day I got up and pushed the clutch pedal down, but the clutch did not disengage. It had gotten cold and I just assumed my slave or master went bad and thought nothing of it. Pedal felt fine, if not slightly stiffer than usual. Drove it to work rev matching. Came home swapped in a new master and slave (Rodneys) and low and behold the clutch felt no different post bleeding and still wouldn't disengage completely. I did notice if I got it moving if I pushed the pedal half way down it would start to disengage but then re engage when i pushed it the rest of the way. (What the heck???). I had just driven through some pretty bad rain, so my brain thought hey, your clutch is prolly rusty, (it had sat post rainstorm due to a flat tire). So I got it out on the street and bumped it with the starter while pushing the clutch down. The car bucked alot but eventually the clutch "broke free" I took it for a 1 hour stop and go drive and the problem went away. Hooray?
Woke up the next morning to no clutch. Pedal feels stiffer than normal for sure. Double checked slave throw. 1.3 inches. Bumped it with the starter, it broke free. Clutch worked fine on the way to work.
On the way home it got really weird. The clutch randomly decides to not work. Sometimes it will throw, sometimes it wont. During the times it wont engage, it does that partial disengagement at half pedal, reengaging at full pedal. It was completely random when it decided to work and not work. If I stopped and bumped it with the starter it would usually free it up but it required this weird combo of put it in first bump the starter, then immediately press the clutch when it starts to roll forward. Parked the car overnight.
Woke up this morning. Clutch pedal is significantly stiffer than its ever been, slave movement is 1.3 inches. Clutch WILL NOT disengage no matter what I do.
Clutch kit is a LUK with a resurface OEM flywheel and appropriate spacer. Please note that this setup was perfect since it was installed 5k miles ago. Rodney's Master with adjustable bango and Slave aswell as a fiero store steel pedal. (I do not believe this to be hydraulic related)
Anyone have any ideas, because I am entirely lost. This goes against my understanding of the clutch system for a clutch plate to randomly stick.
Got an inspection camera? This sounds like a bad clutch disk to me.
I do not, im just bummed that I once again have to take the car apart to do this clutch, would I be able to see it from the inspection port?
Also would a bad disk be more gradual and consistent in its failure. Not one day it works, park it overnight and boom no clutch. And then maybe clutch. I would just expect it to slowly fail and then not work period. I was almost thinking input shaft catching the pilot bearing
you may be able to see if the pad is still on the clutch disk, if you put a camera in sideways at the starter. you may also be able to see if there is a bunch of shredded disk in the housing. I have seen clutch disks go out and the clutch go metal to metal. I have seen them kinda function then melt and fuse to both the pressure plate and the fly wheel or one or both. Just an idea.
Really it could be a lot of things. Bad throwout bearing, warn fork arm that actually pushes the clutch open and closed. I think you need to look inside. From my own personal experience and from reading about all the problems people have with aftermarket clutches, an OEM style clutch just lasts longer with less problems.
Alright, I'm gonna go ahead and take a peak inside when I get home. Its got to be the pad. I also forgot to mention it has a brand new throw-out arm and bearing from the fiero store, so I'm guessing its not that. Absolutely disheartening though.
I will make sure to keep everyone updated. If you have any other ideas please do not be afraid to chime in. Save me from pulling this cradle again
[QUOTE]Originally posted by Dukesterpro: I was almost thinking input shaft catching the pilot bearing[QUOTE]
If you're referring to a pilot bearing in the back of an engine crankshaft, I thought they were not required on front wheel drive design. A bearing in the transmission around the output shaft serves the purpose. If you're using a pilot bearing in addition to that you may be creating a binding situation.
Just my 2 cents.
Spoon
------------------ "Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut
[QUOTE]Originally posted by Dukesterpro: I was almost thinking input shaft catching the pilot bearing[QUOTE]
If you're referring to a pilot bearing in the back of an engine crankshaft, I thought they were not required on front wheel drive design. A bearing in the transmission around the output shaft serves the purpose. If you're using a pilot bearing in addition to that you may be creating a binding situation.
Just my 2 cents.
Spoon
Whether or not they are required. My engine which had never had its clutch changed I am the second owner, this information is from the first owner) and it had a pilot bushing from the factory. So I installed an identical one from the clutch kit. It worked fine for 5000 miles of pretty solid stop and go.
Also as a update. I got into the car after work and the clutch is working fine. Drove it about 50 miles with no issue. Stopped at the store to get some bread. Got back in. No clutch. Drove it home. Parked it. Started it this morning and the clutch works perfect.
Im still working on getting it apart but you guys have to admit this is weird as heck.
Whether or not they are required. My engine which had never had its clutch changed I am the second owner, this information is from the first owner) and it had a pilot bushing from the factory. So I installed an identical one from the clutch kit.
From what I understand, the manual transmission input shaft doesn't actually reach the crankshaft pilot bushing in a Fiero application.
From what I understand, the manual transmission input shaft doesn't actually reach the crankshaft pilot bushing in a Fiero application.
That is interesting news, I wonder why they would go through the process of installing them then. Maybe when the flywheel is made they preinstall them for other vehicles? But what other vehicles would use that flywheel and need one where the fiero wouldn't?
Maybe when the flywheel is made they preinstall them for other vehicles? But what other vehicles would use that flywheel and need one where the fiero wouldn't?
I think you're getting confused as to where the pilot bushing is located.
During your last assembly how much run-out (horizontal & vertical) was on the transmission output shaft. Also output shaft diameter at the tip versus the pilot bushing internal dimension. Tech manual may give you the minimum & maximum spec's. Too tight = binding especially when thing warm up. Too loose = wobble and excessive wear. That info will go a long way if indeed the input shaft is long enough to engage the pilot bushing with the proper depth.
I can relate to your issue. On the job there was a fleet of International DT466 diesels with auto trans. The automatic trans in one would always fail and the local dealer would rebuild or repair it under warranty. On the 3rd failure the breakdown was closer to another International dealership so it was towed there. They discovered that the transmission was the wrong one for that vehicle rating, hence all the failures. Apparently they were short on transmissions at the factory and they substituted whatever was available to keep the line going.
My personal experience ordering a new Dodge van in 1973 for self customization. First day all the dash gauges went up in smoke. Took it back and all gauges, sending units, etc, were replaced. This went on and off for 2 years and I traded it back in at same dealer. Two owners later I saw it in a driveway and a guy was washing it. I told him I was the original owner and the problems I had with gauges. He had the same issues and it turned out to be an under rated alternator not able to maintain proper voltage when all accessories were being used. The voltage regulator for the sensitive gauges would allow an over voltage condition wiping out the gauges. Another case of it came from the factory that way. Probably ran out of the proper alternator and slapped one on to keep the line going. It happens...but not enough for a factory recall in these cases.
Spoon
------------------ "Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut
Thank you for the stories, the one about the van was particularly funny, definitely wouldn't expect that out of a new car.
I am not entirely sure what the term runout means. But I will describe everything I can in the general vicinity. The input shaft has no wobble and appear to have no wear around the tip. if you pulled or pushed on it, it would move no more than a millimeter. The pilot bushing is the stock one, it has a inversed conical lip that lead to the center bore. Sizing is nearly identical to the original one by a few thousanths.
To be clear the last clutch was replaced to an unrelated issue, the clutch itself was still good, the throw out bearing had collapsed and was screaming away. And the clutch disk appeared to have been overheated and was slipping real bad. Tons of black clutch material in the bellhousing as well a snapped clutch fork finger that had been grenading around the inside of the bellhousing and left hundreds of little pockmarks everywhere.
over the last two days and this morning the clutch has been on and off working fine. Sometimes you get in and the clutch wont give you a issue the whole way you drive, until you park and shut off the motor. Then when immediately try to start the motor again locks up and wont disengage. It seems to do this entirely randomly. Never really seems to lock of up mid drive. (If it doesnt get stuck in the first couple actuations it wont get stuck until you shut the motor off)
When the clutch is working, it works flawlessly with no weird smells or sounds and it engages very nicely aswell.
Im still working on getting in there, but I just wanted to provide all the information that I can
ok so what throw out arm do you have? you said you got the Fiero store one is it the cast one? did you also replace the fork? just starting to sound a lot like when the stamped steel arm cracks. OTOH about 6 months ago I picked up a project car cheap for having a similar issue. The dude said the clutch was shot. But It was like it was not disengaging. I messed with it and was able to get it to work fine a few times. I ended up pulling it apart and the throw out bearing was off the fork and the fork was cracked and bent.
ok so what throw out arm do you have? you said you got the Fiero store one is it the cast one? did you also replace the fork? just starting to sound a lot like when the stamped steel arm cracks. OTOH about 6 months ago I picked up a project car cheap for having a similar issue. The dude said the clutch was shot. But It was like it was not disengaging. I messed with it and was able to get it to work fine a few times. I ended up pulling it apart and the throw out bearing was off the fork and the fork was cracked and bent.
I actually misspoke, I replaced the clutch fork not the stamped steel arm.
I always figured a cracked arm would be a permanent issue and not a intermittent failure, nor would I think that bumping the clutch would cause the arm to work again. So to be honest I haven't pulled it off too look. I do know that mine is the original stamped 84 one that came with the car. I will pop it off tonight if this rain lets up!
yeah so im thinking the arm is cracked. When its cold the arm is more ridged and transferring more movement to the the actual fork. Once it warms up it bends more and is not transferring motion to the fork. just a thought.
yeah so I'm thinking the arm is cracked. When its cold the arm is more ridged and transferring more movement to the the actual fork. Once it warms up it bends more and is not transferring motion to the fork. just a thought.
Oh i sure hope you are right, that would be such a cheap and easy repair. But I feel like its less heat related then you are making it out to be. I can get it to get stuck just by bumping the clutch even if its ice cold. Also the fact that the pedal gets hard to push rather that softer. It still also wouldnt answer while bumping the starter and dancing on the starter would get the arm to grab again.
I hope this awful rain lets up soon. Its a downpour out there. I need to investigate! I need answers!!!
Looks like its a worst cast scenario, its in the bellhousing. I checked everything. The clutch arm is in good shape, no cracks. Perfect Hydraulics. (even when its not shifting its still moving the correct amount) It just doesn't want to fully disengage randomly. After continuing to drive it it seems as soon as you "break it loose" by bumping the starter and pushing the clutch after the car starts to roll back. It works fine. But as soon as you shut the engine off and park, its stuck again.
Does anyone know if the inspection plate allows me to see the fork, TOB and shaft, or am i just going to be looking at the back of the flywheel. I just want to peek inside to see what Im dealing with.
removing the starter should allow you to see inside with a camera. otherwise there is not much gap between the flywheel/ring gear and the bellhousing. if you don't have an inspection camera, i wouldn't expect to see anything more than a tiny peek of the fork shaft.
Maybe cracked or broken friction material. When its spinning and free it remains free then shut it down and it gets jammed up again.
Honestly, if its that bad I'm surprised your still driving it. I would tear it back apart to find the problem, it should be pretty obvious when you see it.
[This message has been edited by RichLo1 (edited 11-07-2022).]
removing the starter should allow you to see inside with a camera. otherwise there is not much gap between the flywheel/ring gear and the bellhousing. if you don't have an inspection camera, i wouldn't expect to see anything more than a tiny peek of the fork shaft.
The auto parts stores near me will lend an inspection camera for free - might be worth a shot.
New clutch kit is in, going to be doing the fix this weekend.
I have been doing some reading and it looks like some miatas were recalled in 2015 with the exact same problem of a randomly moving actuation point on the clutch and having to bust the clutch loose with the starter sporadically was due to pressure plate bolts backing out.
Are fiero pressure plate bolts torque to yield or are they reusable?
If they aren't reusable what can I get as far as replacements go for a 84 4cyl?
I am not a know it all, but I believe you need to drop the transmission to get at those. This would be a procedure that will at least give you a total inspection of your clutch issue
I have pulled this engine, transmission combo meal 3 times on this car alone. Its not the end of the world, and I have a pretty good system worked out, I can usually go full out to full in, in just about 6 hours. Its just dirty long work and I don't want to do it. lol. Looks like its coming out this weekend after all.
Somebody start a raffle. I believe its a damaged clutch disc or the fork is out of alignment with the throwout bearing.
Spoon
------------------ "Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut
And the raffle results are in, everybody loses, go home!
I kid.
Nah I open the bell housing to doomsday. Against all odds, the brand-new fork from Fiero store with less than 5k miles on it broke. And created the weirdest clutch issue I have ever experienced. 1 Finger on the fork snapped clean off. And the remaining fork put a bend on one section of the throw-out bearing flange. Which was why my clutch was randomly working and not working. When the good remaining fingerer was touching the bent area there wasn't enough throw to disengage the clutch. When I would bump the starter it would rotate the bearing to the nonbent area and the clutch would work until it would settle back to the bent side. Sigh. I did notice significant wear on the face of the bearing and the fingers of the pressure plate. No significant wear on the frictions surfaces.
What would cause a brand-new fork to lose a finger? Please keep in mind this is my second fork, my original one was broken in the same way, But I don't see anything wrong. It was installed correctly on the bearing, has good movement and the tranmission shaft has zero wobble. Any Ideas?
I don't have enough experience to argue about what the Fiero store is or isn't. I can say they have been helpful on the phone into sourcing a warrantied replacement fork, and I still don't know for sure what the root cause is here.
If you believe there is a better alternative to the Fiero stores clutch fork please inform me. But as of now they are the only trusty-worthy folks making them, that I know of. . .
Back to the drawing board.. Your replacement clutch is a LUK brand, clamping force in pounds not mentioned but I'm assuming it is much stronger than the factory stock clutch. The stock slave cylinder & seals, Clutch Arm and fork, release bearing were engineered to engage a clutch with xxx lbs of force and maybe a little extra. Grandma herself could handle this setup. Little Johnny comes along and installs a super duty clutch that takes both feet on the pedal to disengage. All the remaining stock working parts now have to endure this heavy load they were not designed to support. Results could be bent clutch pedal, broken clutch arm, bent clutch fork, damaged throw-out bearing, internal seal leakage in slave cylinder and early failure of the clutch system.
Hydraulic floor jacks, engine hoists and bottle jacks have a rating on them to not be exceeded. Unfortunately clutch assemblies don't mention anything. They just give you the clamping force of the clutch and the rest is up to the buyer to figure out or not.
Perhaps The Fiero Store clutch fork was designed for OEM clutch assemblies.
Bottom line may be to seek out the weak links in the system and improve with the best quality parts you can acquire.
Just my 2 cents...
Spoon
------------------ "Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut
I got concerned that maybe the LUK kit which seems to be very popular, is over spec, I gave LUK a call. (Was a absolute mess trying to get a phone number) Looks like the 04-077 has exactly the same clamping force (he gave me a number, I forgot it) as the OEM assembly. I decided to test this out by standing on my original pressure plate and my LUK plate. Through this incredibly crude test I discovered the LUK plate is actually slightly SOFTER than the OEM springs, even though they are 38 years old.
I'm starting to think I might just have gotten unlucky with this fork.
Does anyone see any unusual wear on the face of the pressure plate. Most cars I have done clutch jobs on typically look something like that. But does anyone see anything obviously janky?
I gave LUK a call. Looks like the 04-077 has exactly the same clamping force as the OEM assembly.
That's in agreement with everything I've read here over the years regarding the LUK clutch kit. It's basically a direct replacement for the factory unit.
I decided to test this out by standing on my original pressure plate and my LUK plate. Through this incredibly crude test I discovered the LUK plate is actually slightly SOFTER than the OEM springs, even though they are 38 years old.
You may want to research clutch clamping pressure versus torque, weight of vehicle, etc...
Spoon
------------------ "Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut
