Hi y'all, Here's what's happened, maybe you will be able to help. I just bought my first Fiero. A 1984. It arrived with a bad clutch, slipping under heavy load and a screaming throw-out bearing. Please note the car shifted into gear just fine, it was drivable just annoying.
I dropped the cradle, pulled the motor and trans. After two attempts of purchasing a Luk clutch and receiving incorrect parts (they were shipping this weird internal slave setup instead of a throw-out bearing, I ordered an O' Reilly's clutch kit which seems to have fit perfect, It included a throw-out bearing, pilot bearing, disk and pressure plate (I did not end up using the pilot bearing, as I couldn't get the story straight about which one is right so I left my old pilot bearing in its place, just cleaned it up good) . I also noticed that one of the fingers on my throw-out arm were broken and the arm was really hard to turn, so I ordered a new Arm, Bearing Set and Seal from the Fiero store and installed them as well. Since 2.5L flywheels seem to be as rare as hens teeth, I had it resurfaced. I didn't measure the original thickness, but it doesn't appear they took much off, it wasn't in bad shape to begin with. All was good in the world, so I reinstalled everything and buttoned back up.
I go to fire up the car and low and behold it wont go into gear, I can shift it fine with the engine off. When in first I started it and hit the clutch and the brake the engine stalled. I appeared to be getting pretty good throw at the arm, but I decided to bleed the system down anyways, I was able to measure 1.25 inches of throw at the arm but still no clutch disengagement. Unfortunately the voices in my head made me start doubting that I installed the clutch disk the right way. So I dropped the cradle AGAIN and pulled the transmission. Nope everything appears to be installed correctly.
I am at a loss. Especially as it shifted fine before and I am getting proper throw on the slave, which leads me to rule out the bent pedal problem. What am I missing??? Sincerely,
Pulling my Hair out!
------------------ My girlfriend said she's is gonna leave me if I by one more car, I sure am gonna miss her.
I went through clutch replacement a few years ago with an 86 2.8 engine with an Isuzu 5 speed; an unusual swap on the transmission. After buying a clutch kit, I found out it was not the same as the one in the car. So being in Mexico where parts are hard to get anyway, I had the clutch disc resurfaced, and pressure plate and flywheel cleaned up without taking much meat off the steel surfaces. Even doing a little bit of this might put you at risk of changing all the dimensions inside. It was suggested a shim in between the flywheel and the crankshaft to compensate for this, and return it to its old tolerances. I did that ( have forgotten how thick the shim was) and maybe got lucky. Everything worked fine, and still does 7000 miles later. I am no expert- maybe someone more seasoned with the .Fiero might have other suggestions.
First step is to check the throw on the slave cylinder and make sure you're getting at least 1". If not try to bleed the system. Same as doing brakes. One person on the pedal and the other at the bleeder valve.
Second are you sure you installed the clutch disc with the correct side facing the engine?
------------------ formerly known as sanderson 1984 Quad 4 1886 SE 2.8L 1988 4.9L Cadillac 1988 3800 Supercharged
You need the slave to be moving 1-1/16 to 1-1/4 inches.
quote
Originally posted by Dukesterpro:
I decided to bleed the system down anyways, I was able to measure 1.25 inches of throw at the arm but still no clutch disengagement.
"the arm"? What does that mean exactly? The clutch arm that the rod from the slave pushes against? If so, have you had a good look at it to make sure it's not broken?
I'm also a firm believer in needing to install a shim when the flywheel has been resurfaced, as discussed in This thread.
[This message has been edited by Patrick (edited 08-08-2022).]
You need the slave to be moving 1-1/16 to 1-1/4 inches.
I'm sorry yes, I said arm I meant the slave cylinder is extending 1.25 inches.
The clutch lever, the black stamped steel one that interacts with the slave pushrod is not broken. I inspected it when I Installed the new fork. (The rod that goes through the bellhousing and holds the throw-out bearing)
So did me not using a shim really throw the geometry off that much? Where do I get a shim for an Iron Duke?
So did me not using a shim really throw the geometry off that much?
Hard to say. It might depend on how much material was shaved off... not only this time, but previously.
As you well know, it's a lot of work dropping and re-installing the cradle... so be open to any other suggestions!
quote
Originally posted by Dukesterpro:
Where do I get a shim for an Iron Duke?
Flywheel shims are the same for the duke and 2.8, but there are different thicknesses. I used a .025" shim from RockAuto. No, I don't know which thickness you might require.
I just wanted to add that plenty of slave travel is critical with the Isuzu 5-spds, not nearly so critical with the Getrag 5-spds. As a matter of fact, with too much slave travel with the Getrags, disengagement gets worse. (I had to shorten the adjustable banjo in my Formula to reduce its slave travel.) I have no experience with the Muncie 4-spds. When you had reassembled everything, did you try shifting (with the engine running) and not pressing the clutch pedal all the way to the floor?
[This message has been edited by Patrick (edited 08-08-2022).]
Well, I have decided to hit it with the metaphorical parts shotgun, I bought 2 different clutch kits, and 3 different shims. Gonna bring these bad boys in and try slapping it back together. I currently have the engine and transmission out, so if anyone has any other ideas let me know!
I have already email Rodney regarding the issue, and he has already responded about replacing my failed parts, so please be clear this is NOT me criticizing Rodney's parts, I am 99.999% sure this was an installation user error. I only want to disclaim this so no one thinks trying to imply anything other than that I am messing up something somewhere.
84 Fiero SE, Muncie 4spd.
Anyways, I went ahead and added a 50/1000s shim to my flywheel, reinstalled and still found I have no clutch throw. I bit the bullet and purchased Rodney's master with adjustable banjo and slave. This is what happened.
Prior to installing the Master/Slave. I was unable to get enough throw at the clutch arm to disengage the clutch. I ordered a new Steel Pedal from the Fiero store and installed it without the redundant return spring. I then installed bench bled the Master cylinder per the included instruction and installed it with my old slave cylinder, I had the adjustable banjo turned out approximately 2 turns longer than the stock push rod and of course have the banjo facing up. I bled per V8 Archies instructions. (Pedal Down, Crack Bleeder, Close Bleeder, Pedal Up. Repeat. Upon the last bleed cycle remove the bleeder, push the piston back. Close bleeder release.) This allowed the car to shift, however the clutch wont disengage until the absolute bottom of the pedal travels. You have to push it hard into the floor to get it to shift. I figured that this was a result of using my old Slave (even though the old slave showed no signs of leakage) so the following day I replaced my old slave with your new one. I repeated the same bleeding procedure, after the bleed was complete, I ended up with less throw (15/16th of inch vs 1 1/16) than with the old slave. Figuring that this was a result of a poor bleed I kept attempting to bleed and rebleed with no results. I immediately noticed that the piston on the master was coming up very slowly during the bleed process, frequently getting stuck down and taking 30+ seconds to return. I also noticed fluid in the boot of the slave cylinder a little bit after the master began to stick down. After removing it to see where the leak was from, I noticed the piston can slide right out the end, and appears to be lacking a snap ring. I decided to put my old slave back on but determined the master was now stuck down and the pedal was not coming back up.
I am using Prestone DOT3, if that's relevant.
I am using a LUK Clutch with a resurfaced stock flywheel and a 50/1000s shim. I have noticed that when the slave is removed I have about 2 inches of play at the throw-out bearing if I pull it away from the pressure plate. I can push the throw-out against the pressure plate fine. This has been mentioned to be normal to me, but I figured its worth mentioning.
My clutch arm is not cracked, and my fork is new with new bearings and a new seal.
Tell me Fiero people, what am I doing wrong? I just cant imagine there is enough air in that system to be short 2 inches of pedal throw and have the actuation point on the floor. I'm getting desperate here, haha. I just want to get more opinion before continuing.
A couple of questions just for more info. If I recall, the 84 used a different slave than any of the other years. There were 4 different length slave pushrods. One for the 84 4-speed, one for the 85-86 4-speed, one for the 85-88 Isuzu, and one for the 86-88 Getrag. Are you sure you have the correct slave pushrod? If it's too short, your slave will bottom out before the clutch releases.
Edit: To correct what I said about the different pushrods. The 85-86 4-speed and the 85-88 Isuzu slaves were the same and used the same length pushrod, so there were only 3 different lengths. Rodney says his 85-86 pushrods are 144mm long while the 84 pushrod is 138 mm long.
When shimming the flywheel, the shim thickness should be equal to the amount cut from the face of the flywheel.
[This message has been edited by fierofool (edited 08-23-2022).]
I can not confirm that I am using the correct pushrod, but I can confirm that the replacement pushrod from RD is the exact same length as the one that was there previously. My old slave is actually aluminum, my understanding is that 84s have aluminum slaves originally. During my disassembly it appears that nothing on this Fiero has ever been removed regarding its clutch, which seems likely due to the low miles. I can confirm that the old slave, which I verified has a snap ring, does not leak or bottom out when operating the clutch. I confirmed this by detaching the pushrod and stepping the pedal which goes solid as soon as the slave bottoms out.
The shim I installed is thicker than the amount of the flywheel taken off. My understanding from previous cars where I have shimmed flywheels is that the shim must be the same or greater (to a limited amount) than what was removed. I removed about a total of 40/1000s of material and the shim is confirmed at 50/1000's
I ordered a new Steel Pedal from the Fiero store and installed it... I had the adjustable banjo turned out approximately 2 turns longer than the stock push rod...
I understand that the possibly defective RD master and slave units have momentarily put things on hold, but I have a question about your banjo length.
Ordinarily an adjustable banjo is used to compensate for a bent clutch pedal. It allows a certain measure of lost throw to be recovered. When you lengthened the adjustable banjo to be "2 turns longer than the stock" with a new clutch pedal, were you still allowing for some free play at the top of the pedal's travel? Is it possible you lengthened the banjo too far and the clutch master wasn't able to fully return to the end of its travel? In other words, is it possible that the master was never being fully released?
[This message has been edited by Patrick (edited 08-23-2022).]
I read all of your replies and think I know what you are going through.
My 86 clutch was replaced with similar problems, and I went through several different paths trying to get it working, including replacing the slave cylinder.
I ended up using a vacuum pump to draw the DOT3 fluid into the slave from the master. It took two people to get it done, but it was near perfect afterwards. One person watched the fluid drawn out of the slave cylinder into a catch bottle, while the other person kept the master filled with new DOT3.
Once the system was opened, and the new slave was installed, the amount of air that had to be removed was the tripping point. Trying to do the job myself meant that occasionally the master would run out of fluid, and the air would be in the line again! By having a second person to fill the master, while the other watched for bubbles in the catch bottle allowed the pump to be turned off when no more air was detected.
I think I wasted about a gallon of DOT 3, but the system was clean and water free afterwards!
I don't look forward to the job it will be after I do a 3800 swap into that car....
About resurfacing the flywheel, I do that every clutch change, but I have two flywheels I use to ease the job. Once I have the 3800 installed I will have two spares for the 2.5L.
[This message has been edited by crashyoung (edited 08-27-2022).]
The bolts holding the entire pedal assembly worked there way loose and the whole assembly was flexing with the pedal. Bolted them babies down tight and low and behold clutch works good!. I did end up needing that spacer! For anyone planning on having there duke flywheel resurfaced!
