Diaphragm vs. release lever pressure plates

[bull]

I talked to my tranny guy today regarding a new clutch kit and he recommended I get a diaphragm pressure plate setup over the OE-style release lever pressure plate. He said they are a lot more user-friendly, quieter, fewer moving parts, etc. (if I remember his verbiage correctly). Do you guys have strong opinions either way?

From Summit:
Pic 1. diaphragm style
Pic 2. release lever style

[Ghoste]

The diaphragm style needs less input pressure from your leg to release so it's nice for girls and Chevy lovers.  On the bad side, it has a bad reputation for hanging up at high rpm and being a generally weaker setup overall.

[bull]

What about old men?

While I'm at it I might as well ask about the clutch disc itself. My tranny guy also said to stay away from all the fancy stuff like kevlar and stick with the more OE-style material. So what was OE? Organic or semi-metallic?

[Ghoste]

I probably agree with him on that.  I've never had a Kevlar disc but my understanding is that they tend to grab, can't say from experience though.

[John_Kunkel]

It's pretty hard to find other than a diaphram clutch in newer cars. The Viper, Vette and killer diesels kinda bust the myth about them being a "weaker setup".

Many muscle era cars need to have the pedal overcenter spring removed when changing to a diaphram clutch, the pedal will often stick on the floor even with the engine off.

[Cooter]

I've run both and I was one that was a firm believer in that the diaphram was weaker....Well, after five Borg & Beck Lever type pressure plates behind a well prepped 440, I am a believer in the diaphram Pressure plate now....All were 3500 LB Pressure plates and the diaphram is still in there....

[bull]

Thanks guys. I'll be going with a diaphragm setup then, even though Ghost's advice is usually pretty sound. Like John said though, it's next to impossible to find release lever pressure plates on any modern application and if they're good enough for Vipers, Challengers, Rams, etc., they're good enough for my 383.

[Ghoste]

I said reputation though, not personal experience.   

[bull]

I said reputation though, not personal experience.   

So, regarding my other question. Were the OE discs organic, semi-metallic or something else?

[A383Wing]

I said reputation though, not personal experience.   

So, regarding my other question. Were the OE discs organic, semi-metallic or something else?

I thought the OE ones were asbestos...or something like that. They are probably organic now

I have a diaphragm plate on the black 66...it does not work as well as my 3 finger one in the cream 66...the "feel" is too light, and it won't grab as well....and as mentioned, at high rpms, I have had the pedal stay on the floor between shifts...not a good feeling

[Ghoste]

I thought asbestos was organic?

[Iron Chef]

Many muscle era cars need to have the pedal overcenter spring removed when changing to a diaphram clutch, the pedal will often stick on the floor even with the engine off.

New to the board here and I have this problem now and again.  I need to put in a new clutch as it is, but could someone explain a bit more in depth about the clutch sticking on the floor problem and how to resolve it?

Thanks!

EDIT: Did some searching and found the answer.  Thanks.

[A383Wing]

I thought asbestos was organic?

You knew what I meant.

[Ghoste]

Actually I didn't Bryan, I think I get it now.

[Chryco Psycho]

I won't run a diaphragm , I use McLeod PP & Discs including Kevlar & Feramic discs
I have seen the Cforce diaphragm not last 1 weekend , I have had them hang on the floor ....good thing the cars had rev limiters  . I also do not like the feel of them , no pressure as you raise the clutch then it suddenly snaps over , hard to launch smoothly . You will not find a diapragm in my cars

[elacruze]

Diaphragm spring pressure plates need to be adjusted carefully. If they throw too far, they overcenter and centrifugal force can be more powerful than the springs and cause them to remain disengaged. The solution is to adjust them to release but not to overcenter. It's been a long time since I had to play with one (1980, bowtie). I'm installing a centerforce in my car just so it's easier to drive, considering that my GF will drive it and with the long tours planned I more than likely will get stuck in traffic somewhere (Atlanta, anyone?)
I've had a 3500# Borg and Beck in mine since 1982 and it's been fine, although relatively low mileage, aluminum flywheel and no slicks ever. I just think it's a little too tough for touring.

The only clutch failure I've seen in person (mechanical failure that is) was the hub springs coming out of an old Chevy pickup...anybody here routinely break clutches?

[Cooter]

Well prepped 440 on slicks, and a Dead Hook...You'll need a mask for all the clutch dust coming through your Heate ducts.....

[jerry]

that clutch will be fine with the 283 2bbl. sorry i thought you put a chevy engine in a mopar. diaphragm clutch.

[elacruze]

Well prepped 440 on slicks, and a Dead Hook...You'll need a mask for all the clutch dust coming through your Heate ducts.....

That's just weak clamp load, not really breakage.
Who's broken clutches, and what broke?

<edit>
Did I say Borg & Beck? ew. Hayes. 

[Rolling_Thunder]

I like the Borg and Beck style...    I run a diaphram style in my Charger and honestly I like the feel of a B&B style better....      people with a diaphram usualy remove the overcenter spring because it is too much force on the clutch...      with a properly set up clutch you'll be fine     

[A383Wing]