Technical Clutch chatter ,AGAIN!

Well, here's what's happening so far. I put my cheap Harbor freight Dial indicator on the bellhousing and measured it in 3 different spots. Here are the results not a lot but I don't think it's too great. The pressure plate looks just like the one I took out hotspots on 1 side. I'm gonna pull the flywheel and get a resurface by my usual guy and see what he says. And the new clutch from Fort Wayne shows up tomorrow. But I'm gonna be out chasing parts.

 

Just pulled the flywheel off. And it has hotspots in the same type of fashion. Also I measured the thickness of the flywheel and 3 different spots and it seems pretty close. Who the hell knows what's going on?uhhhgh.....

 

I don't trust those loosey-goosey dial supports - they allow movement...

My son was trying to set up a ring gear and pinion and totally frustrated. I told him to trash that support and get one of the "rod & joint" type - after that he was done in 15 minutes.

 

Is the disc built on a Marcel-type sprung carrier between the friction surface's or is it a solid flat-type carrier? The sprung carrier's are much more forgiving.

 

I imagine what you mean by Carrier is the hub? And yes, this hub is sprung, not solid. I know the Dial indicator is Lucy Goosey . But that's all I had. And I got a pretty tight.

 

Not the hub, but between the friction material. You should be able to squeeze it together and see the air gap between the 2 halves disappear if it is built on a sprung carrier. It acts as a vibration damper/shock absorber of sort's.

 

Okay, gacha, I know what you mean, this one seems solid. And here's a pic of the first slipping clutch I took off. It seems like the plates in between It are a little s-shaped, so it's got some gap and squishes.

 

Grind job on flywheel ****s. So does the one on the Ram PP. I got no clue why hot spots so soon after clutch install. I took apart an original 12k mile clutch [I bought the car new in '72] and the machining marks on the PP and FW and Disc were barely worn off, no hot spots anywheres.

 

When you tighten the pressure plate down did you work the bolt down evenly and in a crisscross pattern?

 

Yup, totally even in a star pattern about one turn at a time. And torque to 25 foot-pounds as these are 5/16th bolts.

 

If the flywheel has hot spots, those spots may be hard enough a surface grinder won't remove them, much like hot spots in disc brake rotors can't be turned out. The hot spots will always be a few thousandths higher then the surrounding surface and will reappear as soon as heat returns to the surface.

The pressure plate will have corresponding hot spots because it is clamped to the flywheel so its relationship with the flywheel remains the same. The raised flywheel hot spots will create the first contact point on the spinning disc between the flat new pressure plate and the used flywheel that has the raised hot spots.

If you rotate the pressure plate on the flywheel you might create a new hot spot that may balance the original one out (rotating the pressure plate to the third set of bolt holes helps even more), funky as it might sound. Other wise, the only two fixes are to replace the flywheel (and the pressure plate) or live with the chatter.

At least that has been my experience, yours might vary.

 

Just for general info , this is what the pressure plate surface looks like on mine ( à Luk , the worlds largest clutch manufacturer ,)

 

On most of the cheap ones that I get from the parts store. The surface looks like that, but on this ram pressure plate it was smooth.

 

I’m not convinced there’s necessarily a flywheel or clutch issue. How old was the clutch you pulled out? Is it a stock bellhousing? Can you index the bellhousing easily?

 

I have no idea how old the clutch was, but it didn't chatter. The owner claimed that it slipped. And that's the reason I changed it.

 

I was just wonder if it was slipping because it was knackered but it was knackered because of something other than normal wear.

 

Very unlikely that your flywheel surface is causing the problem. A blanchard type of grinder is used to machine them and they do a good job really quickly. These same machines are used in industrial machine shops to quickly remove surface material and have coolant flushing them contiuously. A grinding wheel will remove the metal whether it hardened or not. Grinding wheels were used to sharpen tool steel cutters for many years. The way the machine works is with a big flat precision table that rotates. The table is magnetic and holds the flywheel with that magnetism. If the flywheel is aluminum, then pieces of common steel are placed on the table surrounding the flywheel and they hold the aluminum flywheel in place when the magnet is turned on. The chances of getting a flywheel thats not flat after grinding are slim and none.....
Beyond that, the disc itself is going to match the flywheel when it is under spring pressure.

I think one of two things are causing your problem. There is either a mechanical interference between the clutch components themselves, or the throw out bearing is not completely releasing when disengaged. This supposes that you are not getting any oil on the flywheel as you said.

The Bing video will show how a Blanchard works.

Bing Videos

 

Just got my flywheel back from the machine shop. And the guy that runs the place says even though It was previously resurfaced , It's as if it handt been, and where the hotspots were at was .020 taller. We shall see what happens. This new disk is sprung in between the 2 surfaces of the friction material also.

 

I put it all back together and like mark says its smooth as a gravy sandwich. I don't think the 0.020 difference on the fly wheel really made a difference, and I'm thinking that the good clutch and pressure plate from Fort Wayne did the trick.

 

Yep, I'm happy it worked out and also happy that I bought the 2 other clutches through summit. And they will take them back for a refund. Now I think I'll finally replace the new chattering clutch that That I got from CW moss that I put in my 41 that I've been dealing with. Just harder to R and R the 41.

 

Glad you got it all working well. Are you sure it was .020 and not .002 ? Just saying, I have never seen anything come off a Blanchard grinder and be that much.....or anywhere near that much from being flat. Large Blanchards are routinely used to grind plates 4 feet across and on both sides to get them flat as well as parallel, thats what they are made to do.
Anyway, glad it solved your problem.

 

Was 0.020 From what the guy said. Needless to say, I'm not gonna go back to that Napa To get a flywheel turned as the place has turned to **** in the last couple years. And the guy that was gonna turn the fly wheel look like he was drunk.