[thewebb1]

Hi Guys and Gals,



My 67 coupe clutch won't release. We took it apart but the mechanic I use can't see anything wrong.
It's a Muncie 4 speed with a Hayes clutch.
Any thoughts?

 

[flat tire]

then the pressure plate is not releasing or you have bent or damaged linkage
how much free play in the clutch pedal do you have?
did this just happen after a new instillation ?
has this been an ongoing problem that got worse?

 

[3d cad]

I have read on another site that some Hays clutches require .7” to release. Apparently some chevys, a vette in the case I read, only have around .55 travel. I think i remember the numbers but if not the gist of that thread was that you cant disengage some Hays on some Chevys. You might want to measure both, which will be a biatch.

 

[thewebb1]

Sorry, didn't measure free play before disassembly.

This has been a problem I feel from the start. the first clutch I burnt out, so we replaced with the Hayes. Never liked it from the start. I was grinding gears in first and third and I had to make sure I depressed the clutch pedal all the way including using my toes. It would get worse after about 20 minutes of driving. My mechanic said it was me not depressing the clutch in fully until it wouldn't disengage at all and had to be towed home and put it up on the hoist and he could see it was hung up. We took it all apart but nothing seemed out of place or damaged. Pilot bushing was good, throw out bearing was good et cetera, et cetera.
Any body else put a Hayes in with a Muncie and a 400cu in small block? Sounds plausible.

 

[bob15]

What bellhousing? GM, Lakewood, etc?

What clutch fork? Have a part number, OEM, Lakewood?

What pivot ball are you using? OEM or a Lakewood?

What throw-out bearing? Tall or short? manufacturer and/or part number? Hydraulic or mechanical?

How is the input bearing retainer tube on the tranny (this is the piece the throw-out bearing rides on)? Smooth or rough?

 

[3d cad]

this isnt a free play dimension. it requires measuring the pressure plate travel, with or without a throwout bearing, to release. Usually done in a press fixture.
any chance you have a tight organic disc?

 

[1968RallySport]

Sounds like you got one of those steel pilot bushings they ship with the clutch kits. Install an oil impregnated bronze bushing from National. Easy way to tell is remove the bushing and see if a magnet will pick it up.

 

[Vega$69]

Simple. If you have to push the clutch all the way with your toes your seat is too far back or your clutch linkage is not adjusted correctly.

 

[thewebb1]

Thanks for the responses,

We think we found the problem. It is in the linkage as previously mentioned. The pivot ball and fork are both worn out If it's not that then I follow the other suggestions mentioned above.

Thanks for all the input. It helped narrow it down

Steve

 

[SoCal805]

OP

It sounds like you have had a "disengagement" issue even prior to the current clutch. If your pivot ball and clutch linkage is worn inducing slop which then does not allow enough throw in the clutch linkage to disengage the clutch. If clutch is barely disengaging cold, once it heats up it gets worse

also +1 on confirming the pilot bushing is a bronze oil impregnated one vs steel. If the pilot drags on the input shaft it will also make the trans hard to shift

Good check once clutch is installed and all linkage adjusted is put trans in gear and push in clutch and have someone rotate the rear tire. If the tire can't rotate or it has heavy drag the clutch is not disengaging so you need to find out "why"

IMHO there is nothing wrong with Hays brand clutches

 

[thewebb1]

Thanks for your added post SoCal805,


It is an oil impregnated pilot bushing.
Good advice not taken lightly.
I agree, Hayes was a very popular clutch when I was in my teens. A long time ago:grin2:


Steve