Clutch Woes! (Page 1/2)
Dukesterpro AUG 08, 01:57 PM
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!

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My girlfriend said she's is gonna leave me if I by one more car, I sure am gonna miss her.

stevep914 AUG 08, 05:33 PM
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.
Dukesterpro AUG 08, 05:36 PM
Man thats what I was worried about someone saying. I just have it in my head that the resurfaced flywheel is to blame
sanderson231 AUG 08, 05:58 PM
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?

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formerly known as sanderson
1984 Quad 4
1886 SE 2.8L
1988 4.9L Cadillac
1988 3800 Supercharged

Patrick AUG 08, 06:11 PM
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).]

Dukesterpro AUG 08, 09:10 PM

quote
Originally posted by Patrick:

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?
Patrick AUG 08, 09:41 PM

quote
Originally posted by Dukesterpro:

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).]

Dukesterpro AUG 09, 10:24 AM
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!
sanderson231 AUG 09, 10:59 AM
Just make sure the correct side of the clutch disc is installed towards the engine. If it isn't the clutch may not release.

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formerly known as sanderson
1984 Quad 4
1886 SE 2.8L
1988 4.9L Cadillac
1988 3800 Supercharged

Dukesterpro AUG 09, 11:40 AM

quote
Originally posted by sanderson231:

Just make sure the correct side of the clutch disc is installed towards the engine. If it isn't the clutch may not release.




That was the whole reason I pulled the cradle a second time, I had it it my head I put it on wrong, but alas, I had the flywheel side to the flywheel