Register now to get rid of these ads!

Technical Clutch Release Problem

Discussion in 'Traditional Hot Rods' started by ramjet 80, Jul 13, 2019.

  1. ramjet 80
    Joined: Jul 12, 2019
    Posts: 16

    ramjet 80

    I am putting together a 28/29 roadster pickup to run at events like TROG or the RPM National, I'm, using a 226 Flathead Ford six with a 1952 Ford truck 3-speed transmission & rear axle. I intended to use a hydraulic clutch release system. However I found it required an extreme amount of pressure to depress the pressure plate. I can barley get any travel with a 24" crescent on the flat end of cross shaft. Have any of you had success using a slave cylinder to actuate the clutch shaft on these early Ford transmissions. I have checked the alignment of the parts involved and removed three springs from the pressure plate. I could sure us some help solving this problem.
     
  2. Jalopy Joker
    Joined: Sep 3, 2006
    Posts: 28,624

    Jalopy Joker
    Member

    something like this? 20190713_190648.jpg
     
  3. What size pressure plate? And does it match the trans/throwout bearing you are using? Some later car plates had the fingers closer together which could be binding.
    But yeah, a truck clutch takes a bunch of force to move.
    If you used an F-1 truck pedal setup you wouldn't need hydralics
     
  4. ramjet 80
    Joined: Jul 12, 2019
    Posts: 16

    ramjet 80

    IMG_1919.JPG IMG_0737.JPG IMG_0740.JPG IMG_1919.JPG IMG_0737.JPG IMG_0740.JPG
    It's an 11" clutch which matches the fly wheel I have to work with. I currently have a brake,clutch, and throttle petal assembly like were used in dune buggies. To go to a mechanical set up I would have to replace all these. If I can't get the pressure multiplication with hydraulics I will have to go that route.
     
    RMR&C likes this.

  5. ramjet 80
    Joined: Jul 12, 2019
    Posts: 16

    ramjet 80

  6. 2OLD2FAST
    Joined: Feb 3, 2010
    Posts: 4,003

    2OLD2FAST
    Member
    from illinois

    Those Girling style mc 's are generally small bore , what size is your mc and slave ?
     
  7. ramjet 80
    Joined: Jul 12, 2019
    Posts: 16

    ramjet 80

    Slave Cyl 7/8 Master Cyl 3/4 I'm inquiring about a McLeod hydraulic throughout bearing, to see if they have one that would work for me.
     
  8. oj
    Joined: Jul 27, 2008
    Posts: 6,312

    oj
    Member

    I use 5/8ths bore MC and have McLeod TO
     
  9. I'm using a 3/4" master and 7/8" slave too. The question is do you get enough leverage with the pedal set up.
     
  10. Maybe it's a bit of an optical illusion in your photo, but it looks like you have a a pretty short lever on the Z-arm where the clutch push rod attaches. Not much mechanical advantage there. Also, if the clutch is in the applied position (foot off pedal) in that photo, it looks like the lever is already well over-center in relation to the Z-arm shaft. When you depress the clutch pedal the Z-arm is going to run out of travel very quickly and things are going to start binding.
     
  11. Inked Monkey
    Joined: Apr 19, 2011
    Posts: 1,834

    Inked Monkey
    Member

    I thought they didn't allow trucks?!
     
  12. never liked the hyd clutch release. However you need matched componets. and the correct linkage geomerty.
     
  13. hook00pad
    Joined: Mar 5, 2013
    Posts: 21

    hook00pad
    Member

    Make yourself an adjustable lever arm to bolt to your TO pivot to allow you to experiment with the lever length. You could do that (as I did) by making a flat lever arm with a round notch at the end to fit the round pivot shaft. Then drill a series of holes radiating out from the center of the shaft which would allow you to select your mounting point at varying distances from the shaft center, effectively varying the lever length. Once you decide on the proper lever length, you can fancy it up as you see fit.

    Al Hook
     
    ClayMart likes this.
  14. typo41
    Joined: Jul 8, 2011
    Posts: 2,572

    typo41
    Member Emeritus

    Remember, you are using hydraulic leverage to stock move the clutch,, its not like your pedal is directly attached to the clutch shaft, you have the leverage of the pedal and the leverage of the z bar.
    On my 40 ford truck with a chevy trans, I cant move the arm back with just my arm strength.
    does it work with the hydraulic pedals? Then you are ok, if not, as mentioned you have a bind somewhere.
     
  15. ramjet 80
    Joined: Jul 12, 2019
    Posts: 16

    ramjet 80

    Thank you all for your input, I've had the pressure plate rechecked at clutch company and removed three springs to reduce the pressure . I measured the relationship of the throughout bearing to the clutch. It just seems to require to much torque to dis-in-gauge the pressure plate
     
  16. 2OLD2FAST
    Joined: Feb 3, 2010
    Posts: 4,003

    2OLD2FAST
    Member
    from illinois

    What are you comparing it to ?
     
  17. I like that flathead Ford six! This is going to be a nice ride.
     
  18. ramjet 80
    Joined: Jul 12, 2019
    Posts: 16

    ramjet 80

    The stock throw out finger cross shaft has a flat on the outside of the case, using a 24" crescent wrench I could not dis-in-gauge the clutch !!!
     
  19. ramjet 80
    Joined: Jul 12, 2019
    Posts: 16

    ramjet 80

    I would like to find someone who has used hydraulics to operate this early Ford cross shaft and made it work.
     
  20. ramjet 80
    Joined: Jul 12, 2019
    Posts: 16

    ramjet 80

    I used a 24" cresent on the cross shaft and could not dis-in-gauge the clutch !!!
     
  21. ramjet 80
    Joined: Jul 12, 2019
    Posts: 16

    ramjet 80

    Are you using a early Ford transmission 1940 to 48 ?
     
  22. ramjet 80
    Joined: Jul 12, 2019
    Posts: 16

    ramjet 80

    what type of clutch and transmission are you running ??
     
  23. oj
    Joined: Jul 27, 2008
    Posts: 6,312

    oj
    Member

    That is a Ram clutch & TH400 in a race transmission (clutch turbo).
    I think the 5/8ths bore with hydraulic TO is pretty standard.
     
  24. Actually a Muncie M20 behind a SBC.
     

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.