Some of you may remember me posting a few weeks ago about needing to replace the clutch in my 4.9/Getrag car.
It still grabs okay in the lower gears, but in 5th, at 3000 RPM, I can stomp the gas and make it slip.

I dropped the tranny and clutch out today, and found that the clutch was not even half worn.







What I also found is that the rivets in the hub, at the edges nearest the clutch lining, were hitting the flywheel.
You can see this in the second and third picture above.
You can also see it in the pics below, if you look around the edges of the "depression" in the center.
It appears to me that they were holding the flywheel side of the disk away from full contact with the flywheel. Or at least interfering with the clamping.





So... what to do?

This renews my faith in the Ram HD clutch, but I'm already this far into it.
(I should mention that this is the only issue I've had with the LSC flywheel - or the whole installation, for that matter.)

I'm inclined to have the center depression machined out a bit (if they can do it) have the friction surface re-faced, and take a scotchbrite to the pressure plate and put everything back together. (I'd thought about doing the machining myself, but I really don't have the tools to do it.)
If I replace anything, I'm tempted to just buy a new disk, if it's available.

Thoughts?

Edit - I finally got around to emailing LSC. They want to fix this, going forward.
Please see my post on 1/9, farther towards the bottom...

[This message has been edited by Raydar (edited 01-09-2016).]

A friend of mine who is doing my wiring on my jeep engine swap reffered me to a place called "tennesse clutch supply." I was talking of having him wire up my fiero after my 4.9 swap gets done and he suggested this company cause they will build you a clutch from scratch. You tell them what its for and what kind of power you want it to hold up against and how you want it to grab and they will make it for you. His brother had a clutch built for a datsun V8 swap pushing 400 hp and the disc and pressure plate they made for the car only ran $160!! Check into it and lemme know how works if you decide to go that route. I hear they really know their shi*.

LSC uses a stock, undrilled Fiero flywheel. The only thing they do is drill the bolt holes. I'm not understanding why you see the flywheel as being at fault. Maybe I'm missing something.

That is a worn out clutch.

When the rivets are hitting the flywheel, the clutch is worn out.

quote Originally posted by Neils88: LSC uses a stock, undrilled Fiero flywheel. The only thing they do is drill the bolt holes. I'm not understanding why you see the flywheel as being at fault. Maybe I'm missing something.

I'm not so sure that that's true. Either that or the Fiero Store RAM clutch is just not compatible. I don't recall anyone else using that clutch and having that issue.

I looked at replacement flywheels at Rockauto. They show a wider "dish" in the middle of the flywheel. (One thing I like about Rockauto... Their pictures and descriptions seem to be accurate. If it's a "stock photo" they tell you.)
http://www.rockauto.com/cat...9208&jnid=634&jpid=0

[This message has been edited by Raydar (edited 08-07-2015).]

This is a pic of the clutch I use with my LSC flywheel. You can clearly see the difference between your hub and mine. Mine is a Fiero clutch and the hub has no issue fitting inside the recess. Perhaps yours was mislabelled by RAM?

What kind of clutch is that? It doesn't have all the rivets in the hub.

To eliminate any confusion, I have marked the rivets that are rubbing, and where they are rubbing on the flywheel.
My clutch came from the Fiero Store. I have looked up the RAM part number on the box on various websites.
It is, indeed, the correct part number for an 88 V6 5 speed Fiero.

[This message has been edited by Raydar (edited 08-07-2015).]

My clutch is a Krupp. Pretty much similar to all the inexpensive 6 puck clutches that you see, but it had some design features that seemed just a bit better than the rest. Downside with 6 puck clutches is normally the chatter, but I never got that with this one. It was also gripped hard right from the first drive (which coincided with the first hard acceleration...).

What do Specs and other popular clutches look like in that area? Have to look and see if they all have rivets at a similar radius to yours.

Thanks for the info.
I can't really comment on the Spec or any of the others. Haven't really paid attention to this particular issue until just now. (Go figure.)
I don't know of anyone else who has experienced this problem, but that's kind of how my luck runs.
I am that person who could inadvertently tear up a crowbar in a sandbox.

[This message has been edited by Raydar (edited 08-08-2015).]

I had a RAM HD clutch in my Formula, and year ago it failed (at about 40,000 miles)......all the hub rivets sheared, or so I thought. Maybe the rivet heads wore down and let go. The pad surface was about half used up (similar to yours). I replaced it with a LUK, which is working fine with the stock 2.8.

edit: when I took a look at the damage, there were loose hub parts and springs, but I did not find any rivet heads.....

[This message has been edited by Gall757 (edited 08-08-2015).]

Okay. Found a machine shop ten minutes from my house. Go figure.
Got the flywheel resurfaced, and the edge of the dish (where the rivets were hitting) beveled at a nice 45* angle.

Original


Reworked


Have another Ram clutch on order, along with new flywheel bolts and a rear tranny mount.
Everything should be here by the middle of the week.

Edit - I was almost tempted to put the same clutch back in, but as much of a PITA as it is to change out, it's worth the price of a new one, especially since you can see the "heat bluing" of the hub, where the rivets were rubbing.

But I will hang on to it, for a rainy day.

[This message has been edited by Raydar (edited 08-14-2015).]

Update...
Got my new Ram clutch. The new disk doesn't look quite as sturdy as the one that came out.
It's only got four springs, instead of the six, pictured, but they're bigger, and they're double springs, where the others are single. So I guess it's a "wash".
The center hub flange is incrementally smaller. This was an area of concern with the first disk. It looked like it might get into the flywheel bolt heads, after the facing wore down a bit. That won't be a problem on the new one. The only reason I didn't reinstall the old one is that the center section is "blued" a bit in the area where the rivets were rubbing. Figure it may be compromised.

Also... There are tons of posts regarding pressure plate bolt torque. The factory service manual specifies 15 ft.lbs. Believe it.
15 lbs sounds stupidly low for the task at hand. So I cranked the torque wrench up to 20 lbs. They still didn't feel tight. Figured that maybe the lockwashers were influencing the reading, so I went to 25.
After doing that, I second guessed myself, and came upstairs and did a search.
Basically, everyone said 15 lbs. No higher than 18.
I decided to remove the bolts and ditch the lockwashers, and retorque them to the proper setting. When I removed them, I noticed that at least two of the bolts were visibly stretched. I'm sure they would have broken.
To add to the damage, I had blue loctite on the threads. Loctite acts as a lubricant, so I actually had them way too tight.

[This message has been edited by Raydar (edited 08-23-2015).]

15 ft lbs? Wow man i could see that as the first round in the sequence but not as a final step. That sounds a little dangerous. I have never heard of any pressure plate being torqued that low.

I know... right?

That's what the FSM says.
But do a search on the forum. That is the "accepted" answer. (And ~25 lbs visibly stretched my hardened bolts, so that's something...)

Keep us posted after you get it back together. I love your car btw. I think the formula fast back is a great look. I will be following your foot steps soon as my jeep gets done before winter. I just bought an 88 coupe i am going to convert to a fast back and I have a 4.9 sitting in my garage so i may have to hit you up after i get started on it.

I have always used 18# w/ blue locktite. It always seemed low to me but I haven't had a PP bolt come lose. FW, yes, PP no. lol

quote Originally posted by BV MotorSports: I have always used 18# w/ blue locktite. It always seemed low to me but I haven't had a PP bolt come lose. FW, yes, PP no. lol

I'll be using 15-18 this time. As soon as I get some more bolts.
My FW bolts were torqued to 50#. Since they're the same thread as the stock Fiero crank, I used the stock specs.

Okay... All is well. Survived the "tourist route" of RFTH, but still got driven enough to test.
I have no complaints. None at all.

Update!
I emailed LSC this morning and got a response from Tom. He was quite appreciative, and has promised to look into this.

From his email...
I looked through the post and I see what you are saying. I really appreciate your input. I can easily open that counter bore up on future f/w's. Someone mentioned in your thread that we "just drill stock flywheels".
We actually manufacture the entire wheel. That's pretty much all we do, make flywheels. We make them hundreds of different motors.
I'm not at my shop right now so I can't look at the drawing but I believe we cut those at 5.000 inches. I can easily start machining them at 5.250 or 5.5000. (or whatever dimension)
If I do that, will that still accommodate the other discs that people are using? I've never had anyone point this out. I have no problem changing them, I just don't want other people to start saying their disc now hangs over.
Let me know.
You can call me during the week if you want to or if you have any more questions.
Thanks again for the input.
Tom,
LSC Performance
(951) 677-8895
P.S. We had to move our shop that we had been in back in June that we had been in for 25 years. You can pass that along on the forurm if you want.
Our new address is
LSC Performance
25839 Jefferson ave.
Murrieta ca 92562


To the point..

The question is, How large should the "dish" be?
I'm thinking it should be back cut for another 1/2" total diameter. Will that still accommodate the disks that everyone is using?

[This message has been edited by Raydar (edited 01-09-2016).]

quote Originally posted by Raydar: Update! I emailed LSC this morning and got a response from Tom. He was quite appreciative, and has promised to look into this. From his email... I looked through the post and I see what you are saying. I really appreciate your input. I can easily open that counter bore up on future f/w's. Someone mentioned in your thread that we "just drill stock flywheels". We actually manufacture the entire wheel. That's pretty much all we do, make flywheels. We make them hundreds of different motors. I'm not at my shop right now so I can't look at the drawing but I believe we cut those at 5.000 inches. I can easily start machining them at 5.250 or 5.5000. (or whatever dimension) If I do that, will that still accommodate the other discs that people are using? I've never had anyone point this out. I have no problem changing them, I just don't want other people to start saying their disc now hangs over. Let me know. You can call me during the week if you want to or if you have any more questions. Thanks again for the input. Tom, LSC Performance (951) 677-8895 P.S. We had to move our shop that we had been in back in June that we had been in for 25 years. You can pass that along on the forurm if you want. Our new address is LSC Performance 25839 Jefferson ave. Murrieta ca 92562 To the point.. The question is, How large should the "dish" be? I'm thinking it should be back cut for another 1/2" total diameter. Will that still accommodate the disks that everyone is using?

My apologies to Tom for stating that they just drill the holes in stock flywheels. Someone had told me that when I was researching the flywheel for my 4.9 build. Good to hear that they make them themselves.

As for the requirements of the dish...you are the first person I've heard of having a problem, so I'm guessing your specs should work for everyone.

Bump for the folks who were gone, over the weekend. Then I'll let it go...