Clutch chatter issue

[Meep-Meep]

Long ago when I had the 4 spd in my 68 RR the clutch began to chatter so I pulled the tranny to investigate. I was running the Borg and Beck pressure plate (OEM style used on MoPars) and found the three fingers to be at various heights. It seemed obvious to me that was the problem so I readjusted the fingers and that seemed to cure the problem. FF to present and my 66 hemi Charger is acting up the same way.

Friday night I pulled the tranny to swap in a Passon OD box I just built and to look at the clutch. The pics show what I found. This P plate is pretty new and you can clearly see the wear pattern is not even. Heat marks on one side and nearly untouched machined surface on the rest. The fingers were uneven as well.

So I decided to get scientific and do some measuring. I mocked up the P plate, disc and flywheel on my mill and with a faced off piece of steel acting as a TO bearing butted up against the quill, I moved the table up and down to actuate the clutch. A feeler gauge was used to check the gap all around and it was not even. I adjusted two of the 11/16" nuts until I got an even drag of a .005" feeler gauge between the disc and plate then tack welded them to lock in place. One nut took 1/4 turn and that is significant. I'm hoping this will do the trick but if not Charlie and I will be back under the car pumping iron and wishing for that brief moment I had a Muncie.

...Just realized pics are in another computer so I'll post them later.

 

[Pops1967GTX]

I’m also running the Borg & Beck pressure plate (OEM style)... I also noticed the fingers can become uneven...... Having a hard time adjusting free play...pedal stops & with a slight touch it returns...... Pressure plate & clutch are good.... Can you adjust fingers with transmission in place?

 

[Meep-Meep]

Yes, you can access the fingers by removing the bell housing cover. Access for measurements also won't be a problem but you will need to depress the clutch and not have it move while you take measurements. I have found that height of the fingers at rest is not necessarily the right answer. Since your access point is in one area you will need to crank the engine over a lot to take measurements, which will make the whole process tedious. Before you go messing with those adjusters see if any have moved and maybe focus on any that are out of whack. Those nuts are staked to prevent movement and are not usually an issue, but as I mentioned, I have had issues with them. When making adjustments you want to only adjust two nuts or you will be chasing your tail.

 

[67 coronet]

since the plate could have unevern were on it,shouldnt you set the plate to the flywheel to get even were all around?then let the disc were back to true.just a thought if you are fine tuning.

 

[Meep-Meep]

I looked at that as well but it made little difference. There was really no wear on the plate other than the polished heat spotted surface, or not enough to matter I thought. My thought was to check the gap as if it were in the car with that disc.

I appreciate the feedback and welcome any and all discussion, experience, etc.. And since I have no idea what I'm doing I'll just call it science and post the results.

 

[72Fourspeed]

Can you get a diaphragm clutch for it ? Would save all the fiddling, or is the clutch fairly new ? Just got my first Mopar stick car, and have used diaphragm pressure plates in every other stick car/truck I have owned.

 

[Meep-Meep]

Yep. And while I was in Reno last weekend I stopped by Summit and got a new pressure plate. This is my back up plan if the B&B doesn't work out. Either way I stand to learn something out of this.

Here are the pics of my test and measure set up.

 

[Moparsr2fast]

The only other thing I can possibly see related to chatter from the hat would possibly be uneven spring fatigue. I agree with 72 that a diaphram setup is a viable alternative. I have had better luck with the diaphrams over the b&b design.

 

[Meep-Meep]

The pressure plate is relatively new, so not much fatigue. But something definitely took a turn for the worse shortly after it went in. I think there were two days of normal operation before it started to chatter. So, crappy springs? Something not quite set up properly? Poor quality control? Made in China and assembled in Pakistan?? Going back to the 80's when I switched to a McLeod B&B pressure plate in my 68 RR (after that first incident) I never had an issue. And I didn't drive it like an old lady either. My back up is a Centerforce diaphragm style and may very well be the replacement from now on. I have heard good things about them. If this fix stays fixed I'll leave it and use the new diaphragm in my 66 bel II hemi car.

 

[Moparsr2fast]

If the springs were made from inferior materials, I don't think it would matter how new they are Meeps... kind of like comps lifters..junk from the get go.

 

[2059]

interesting thread, Thanks Meep. just bought a McCleod dual plate diaphram set up for the '64. Was getting slippage with the B&B style. I'll follow up when installed and if it EVER STOPS F*#%ING SNOWING!!! and i can get i back out on the road.

 

[Meep-Meep]

If the springs were made from inferior materials, I don't think it would matter how new they are Meeps... kind of like comps lifters..junk from the get go.

Not to hijack my own thread, but Comp lifters are junk?? I hear what you're saying though. What product can you trust at this point? I plan to get it buttoned up this weekend so we'll see.

- - - Updated - - -

interesting thread, Thanks Meep. just bought a McCleod dual plate diaphram set up for the '64. Was getting slippage with the B&B style. I'll follow up when installed and if it EVER STOPS F*#%ING SNOWING!!! and i can get i back out on the road.

Those are pricey but I bet they work. I will be interested in hearing about how this works.

 

[Meep-Meep]

OK guys and gals the verdict is in. I got the Charger back together today and took it for a drive. I'm happy to report the clutch chatter issue is gone!! Looks like my diagnosis and repair method was correct. Now let's hope it stays working.