Clutch pivot arm update, 1975 308 GT4 | FerrariChat

Clutch pivot arm update, 1975 308 GT4

Discussion in '308/328' started by Jeff Cowan, Feb 19, 2019.

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  1. Jeff Cowan

    Jeff Cowan Rookie

    Feb 21, 2018
    17
    Full Name:
    Jeff Cowan
    Does anyone have instructions/advice for replacing the early style clutch pivot arm with the later style (80's and up)? I bought a used updated arm and am attempting to swap it in later this week on my 1975 308 GT4. I tried searching Fchat and Google for instructions/guides but haven't been able to turn anything up. If there is a good source of info on this posted somewhere, I would very much appreciate a link!


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  2. absostone

    absostone F1 Veteran
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    Jul 28, 2008
    9,180
    not sure about the setup and throw out free play, but will the updated arm work with the early bell crank arm?
     
  3. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
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    Jan 11, 2001
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    30°30'40" N 97°35'41" W (Texas)
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    Steve Magnusson
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  4. Jeff Cowan

    Jeff Cowan Rookie

    Feb 21, 2018
    17
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    Jeff Cowan
    I’m not sure. Other posts keep referring to a Forza article that goes into some detail about this but no one is posting that article...trying to track that down now.
     
  5. Jeff Cowan

    Jeff Cowan Rookie

    Feb 21, 2018
    17
    Full Name:
    Jeff Cowan
  6. cls

    cls Formula 3

    Jun 12, 2007
    1,663
    Los Angeles/Montreal
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    Chris
    The Forza solution is to drill the pedal yourself and only replace the lever 116472.
     
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  7. Jeff Cowan

    Jeff Cowan Rookie

    Feb 21, 2018
    17
    Full Name:
    Jeff Cowan
    Thanks! Isn’t 116327 also necessary at that point to connect to the new arm?
     
  8. Jeff Cowan

    Jeff Cowan Rookie

    Feb 21, 2018
    17
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    Jeff Cowan
    Aha! Attached is the elusive Forza article on this process. In combination with the service bulletin the process appears well explained. I hope this helps others willing to tackle this task!
    Image Unavailable, Please Login
     
  9. absostone

    absostone F1 Veteran
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    Jul 28, 2008
    9,180
    Funny thing is I had that saved on my desktop. But forget I had it
     
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  10. Jeff Cowan

    Jeff Cowan Rookie

    Feb 21, 2018
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    Full Name:
    Jeff Cowan
    Job is complete! The pedal effort is reduced and it’s a pleasure to drive now. However...this was anything but simple. I hope the following tips help others who may take this on.

    Not stated in the SB or the Forza article is the pivot arm has a completely unique nut holding it on that exists nowhere else in the automotive industry. So a custom tool is necessary to get this job done. I was lucky that I was able to call my shop and borrow their tool—which they custom made just for this ridiculous nut. A photo of the tool is attached. Until you acquire this you cannot do this job. Of course check your nut first as I don’t know if Ferrari abandoned this in later years. My service manual shows this nut but if you’re not looking for it you won’t notice until you’re under the car. The goofy nut is round and polished with four dimples.

    Provided you pass that gate and wish to proceed...

    - I highly recommend not doing this solo. There are times where two heads will prevail. And times where each can be doing different things. It took us 6 hours and probably would have been two days or more on my own. DIY skills will determine total time too. Mine aren’t as good as others.

    - Jack the car to get more than 2-feet under to move around. You only need to lift the left side. Always use jack stands. The front belly pan has to come off to expose the front frame rails to place the front jack.
    - The left engine mount has to come out for clearance around the pivot arm. This is not so straightforward. The engine has to be jacked up to get it out and the bracket has very inaccessible bolts. We got it done but it takes patience. Also the bracket that holds the mount is for some reason a seal for the oil pan so you have to keep it on the car with finger tight nuts to prevent oil leaking. Why...we have no idea.
    - With the custom tool, the removal of the arm is straightforward for any DIY’er. The new arm has to go on a specific way. The 2nd page of the linked file in this thread shows it the wrong way. The 4th page shows it the right way. Took us a while to sort that out.
    - The Forza article explains how to modify your existing clutch pedal instead of buying and replacing the pedal. I don’t even want to think about removing the pedal box. The spring does have to be relocated with a new hole drilled into the tab that is used for the pedal stop. A photo is included below of the hole I drilled. Use care with the bit not to snap it because you are going at an angle vs straight on. It took a while to figure out the correct angle of approach with the drill, your hands and a drop light. A slower RPM cut the metal faster. But first....
    - Remove the front seat to get access to the pedal box area. Forza says some body contortions are necessary and that’s an understatement. It also requires a body type that can fit in there, I am 5’ 8” and trim-ish and I could barely fit. It is also very claustrophobic. You must take care not to break the plastic cover of the outer seat rail while the seat is out and you’re laying in there upside down.
    - To reattach the spring in the new hole it took two of us, one to depress the pedal so you don’t have to fight as much spring tension, while the other mucks about trying to make the connection. It helped to use pliers and open the arc of the spring a bit from the tight U-shape that it is otherwise.
    - The SB states that the Control Arm (6) should be adjusted to 4 and 1/8th inch. That was way too short for us so we extended it such that the other dimension is correct for (2) and (8) as described.
    - Lastly we adjusted the pedal height from the back of the car, nothing has to be touched at the pedal box for this. The clutch does engage right at the end of the pedal travel but since we know it has full engagement there is no chance of slipping. Perhaps others have a better sense of how these adjustments work and can adjust it to engage lower in the pedal while keeping pedal height correct. That is something we left for another day!
     

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  11. absostone

    absostone F1 Veteran
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    Jul 28, 2008
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    welcome to Enzo land!!
     
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  12. Brian A

    Brian A F1 Rookie

    Dec 21, 2012
    3,079
    SanFrancisco BayArea
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    1983 US 308 GTS QV
    Wow! Quite the adventure. Glad you like the result. Yeah, welcome to Enzo land; typical job. … the oil filter is easy to change though.

    We still need to trade cars sometime just to compare.
     
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