New clutch setup won't disengage

[yellow rose]

I may regret opening this can of worms... but why don't you use diaphragm clutches? Or Centerforce?

Oh gawd, weed burner will be along in a bit to sing the diaphram praises.

It's on some threads here. Search it.

 

[DrCharles]

I have read that entire thread last month and wasn't impressed with the repartee, and neither were the moderators as I recall...
[EmilyLitella]never mind![/EmilyLitella]

 

[yellow rose]

Well, some day when I get software that will type what I say, I may do a tech article on pressure plates, discs, FW weight and tuning buy ain't no way I'm going to type it all.

 

[Marcohotrod]

I have seen starting in gear breaking a tooth off an older ring gear

 

[pomonamissel]

@yellow rose , hey bud , your a clutch guy ? if so maybe we need to talk , like you said typing is a thousand words is for the birds . pm me i'd rather talk on the phone if you would . my quest is a 10'' clutch setup behind my 340 6pck in a 64 cuda 4spd of course an a833 .

 

[jbc426]

I'll ask one more time, since I can't easily measure plate departure, does anyone know how far the fork tip must travel to disengage the clutch??
Thanks!

1/2 an inch from zero freeplay, between the clutch fork and the pressure plate fingers, at the throw out bearing. Per McLeod tech line.

 

[DrCharles]

I appreciate the help, but that is still not what I wanted to know ;) I don't know how else to say it - how far does the clutch rod have to move the fork?

However, I got the answer a long time ago by asking Centerforce directly. Their reply:

The disc will be released with an 0.030” air gap. Linear travel at the bearing is 3/8” to release. Bearing load is 500 lbs.​

Then I contacted Brewer's to ask what the ratio of the fork is:

Center of pivot point to center of clutch bearing 3.25"
Center of pivot point to center of clutch linkage eyelet 6.5"
That would be a 2:1 ratio.​

So - with the free play taken up. 3/8" * 2 = 3/4" movement at the original fork actuating rod hole.
I haven't been underneath in a while, but I found that a little more movement was better for full disengagement.

 

[SGBARRACUDA]

I’ve had trouble with clutch release on a few Moparts of mine over the years. Especially using Hd Zoom, Schaffer etc. Biggest issue I found was clutch linkage flex.

 

[yellow rose]

I appreciate the help, but that is still not what I wanted to know ;) I don't know how else to say it - how far does the clutch rod have to move the fork?

However, I got the answer a long time ago by asking Centerforce directly. Their reply:

The disc will be released with an 0.030” air gap. Linear travel at the bearing is 3/8” to release. Bearing load is 500 lbs.​

Then I contacted Brewer's to ask what the ratio of the fork is:

Center of pivot point to center of clutch bearing 3.25"
Center of pivot point to center of clutch linkage eyelet 6.5"
That would be a 2:1 ratio.​

So - with the free play taken up. 3/8" * 2 = 3/4" movement at the original fork actuating rod hole.
I haven't been underneath in a while, but I found that a little more movement was better for full disengagement.

It makes a difference which pressure plate you are using, as they all have different lever ratios. In fact, my cover uses a custom made lever that Cale Aronson uses with the B&B/Long cover.

Also, the ratio of the bell crank can be changed which will make a difference.

 

[DrCharles]

YR, that is all true, of course, but not applicable to my original post when I started this thread back in 2016:

I have a Centerforce Dual Friction clutch setup on a new 10.5" steel flywheel. I fabricated a hydraulic linkage with a Wilwood master and a pull-type slave cylinder to a conventional fork/throwout bearing.

And there is also a "bellcrank" ratio to factor in, dependent on the bore sizes of the master and slave cylinders.