Clutch problem

JasonNC
JasonNC Expert Adviser
I was having trouble adjusting the clutch on a 48 Commodore.  I couldn't get it to adjust out far enough to allow for changing gears when the motor was running without grinding.  The last attempt ended in the clutch going to the floorboard and staying there when I pushed the clutch pedal down.  It's like the pressure plate has given up the ghost as there is no pressure on the cross pedal (with the rubber tips) that releases the throw out bearing.  Any ideas as to the cause will be greatly appreciated.  

Comments

  • Geoff
    Geoff Senior Contributor
    Sounds like the taper pin holding the  yoke to the shaft is sheared, or the one holding the pedal hub to the shaft.
  • JasonNC
    JasonNC Expert Adviser
    Geoff, I'm not understanding what you mean by "the yoke to the shaft" as I'm unclear as to what shaft are you referring to.  Is it the shaft that goes from the adjusting rod to the transmission?  
  • bob ward
    bob ward Senior Contributor
    The pins Geoff is referring to connect the clutch actuating yokes (the 'ears' with the rubber tips or the ears it pushes on) to either the cross shaft from the pedal or the cross shaft within the bell housing.
    The other possibility is that clutch throwout fingers within the bell housing have sheared their taper pins.

  • Glowplug
    Glowplug Expert Adviser
    These are locations where pins are used to secure components to shafts used to release clutch. 
  • Geoff
    Geoff Senior Contributor
    Thank you Glowplug, as they say a picture is worth a thousand words.  I had the  pin shear off on my '39 H CC8 many years ago.   Very difficult to replace, as you have to drill a hole in  the  housing to get access to the  small end of the pin.  
    Geoff 
  • Glowplug
    Glowplug Expert Adviser
    Just another thought,  if the spring is disconnected, broken or the frame anchor tab came out the pedal goes to the floor!
  • JasonNC
    JasonNC Expert Adviser
    Ken, if you are correct, what is the solution to this problem? (Two other people I talked to outside of this forum mentioned the "over centered" theory.)  
  • Geoff
    Geoff Senior Contributor
    Get in and have a look.  It should be staring you in  the face.
  • JasonNC
    JasonNC Expert Adviser
    Assuming that one these pins has sheared off, is there an accepted method for repairing them?  
  • Geoff
    Geoff Senior Contributor
    Yes, replace it!  
  • JasonNC
    JasonNC Expert Adviser
    Funny Geoff.  I had that coming... LOL.
  • bob ward
    bob ward Senior Contributor
    The external taper pins are #5 size, the two internal taper pins holding the throwout fingers to the cross shaft inside the bell housing are #4 size. As well as new taper pins you will also need a #5 and/or #4 taper reamer.
    None of this taper pin replacement work is easy to do under the car, realistically its a parts on the bench job.
    Full disclosure. Removing and replacing taper pins can be a PITA even when you have the parts on the bench.
    Take a good look at all the pins in the system before reassembly.
  • Geoff
    Geoff Senior Contributor
    Sorry Jason, I couldn't resist.  It's not so difficult  replacing  the one on the outer end, and from memory the finger assembly has two pins, so unlikely to be in there.  On earlier  models with the  shorter shaft, if the pin shears holding the  lever assembly then you have to drill a hole in the housing to be able to drive the broken pin out, as the large end is at the rear.    You must have a good solid punch and a heavy hammer, and solid "energy sink" like a 5lb hammer head or anvil  behind the  assembly when you try and drive the pin out.  Have fun.
    Geoff 
  • JasonNC
    JasonNC Expert Adviser
    I took the transmission out and removed the pressure plate.  The only thing that seems way out of whack is the throwout bearing is extremely lopsided. There are gouge marks on the surface of it that seem to have caused by the throwout fingers of the pressure plate. My guess is that this may be the source of my problem.  I can't see any evidence that the taper pins are sheared. 
  • lostmind
    lostmind Expert Adviser
    Photos?