Help! 355 T/O bearing (very technical) | FerrariChat
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Help! 355 T/O bearing (very technical)

Discussion in 'Technical Q&A' started by tim355, Nov 5, 2004.

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  1. tim355

    tim355 Karting

    Nov 7, 2003
    57
    #1 tim355, Nov 5, 2004
    1. I'm replacing my cluch, pressure plate and throw out bearing on my F355 and have the following question for anyone that has done this. I need to know which way the large seal (closest to the gearbox) in the Throw-Out bearing is installed? The seal is flared outward on one side. Should this flared side point toward the gearbox or away from it? You might ask , well which way did the off unit point? The one removed is an old style with 3 blue o-rings in it and I can't use it as a reference. Any help would be greatly appreciated!

    2. Is it easy to bleed the clutch system when I'm finished? I see there is a bleed screw at the bottom of the gearbox housing. Is it just a matter of having my wife press on the clutch and hold while I open the bleed screw?
    Thanks again!!!
     
  2. RF128706

    RF128706 Formula Junior

    Apr 8, 2004
    280
    #2 RF128706, Nov 6, 2004
    Hi Tim,

    perhaps you could post a couple of pics of the seal. That would help. If you are talking about the main hydraulic seal then the principle is that the hydraulic pressure forces the flared tip to close up against the metal sealing surface. The flat face goes towards the gearbox, while the u section faces into the hydraulic fluid. To be 100% post some pics.

    Bleeding the system is very easy. I use a 1-man bleed kit with no problems. Other than making sure the fluid level in the reservoir does not fall too low, one other thing to watch is that you don't overfill the reservoir when you've finished. The ABS pump needs some expansion space to cycle. If you put too much in it will leak out.

    RF.
     
  3. tim355

    tim355 Karting

    Nov 7, 2003
    57
    #3 tim355, Nov 7, 2004
    Thanks very much RF!! Your reply was just what I needed! I installed the seal just as you suggested and have bled the system. Everything feels great except it now seems I have quite a bit of extra play (it feels like it's about an inch of travel before I get pressure) at the top end of my clutch travel. I'm not sure if this is the way it was before (I wish I had written down (so I could remember) how the clutch felt before I replaced it) or if I just feeling things differently now and am overly sensitive.
     
  4. RF128706

    RF128706 Formula Junior

    Apr 8, 2004
    280
    #4 RF128706, Nov 7, 2004
    Tim, glad I could help. It sounds like you may not have got all the air out of the system. As a quick check pump the clutch pedal 10 times in rapid succession, then on the 11th pedal stroke check the travel. If the freeplay feels like it has gone then it's air in the system. You need to be quick because the effect of compressing the air lasts for only a few seconds.

    If you still have an issue then it could be something going on with the new release mechanism you've fitted (unlikely) or the pressure plate (did you fit a new pressure plate & friction plate ?).

    As an absolutely last resort you can actually adjust the clutch pedal. DO NOT DO THIS unless you are 100% sure everything else is A-OK.

    More important than the travel "feeling" is the actual clutch bite-point, does the clutch start to engage about mid-way through the pedal trave (correct)l or nearer the bottom (wrong) ?

    RF.
     
  5. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    29,256
    socal
    #5 fatbillybob, Nov 7, 2004
    I think it is very difficult to get the air out of these clutches. IMO to do the best job you need two people and to elevate the rear of the car on jackstands. This positions the airbubble to be pushed out upon bleeding. Also, in the 348's the clutch inlet line is higher in the reservoir that you think. It is very easy to bleed down and suck in air and still have a quart of fluid in the reservoir. If you took out the flywheel there is an adjusting hex head pin that adjust relative position of the pressure plate fingers to throwout bearing. It is the funny hexnut that nobody knows what to do with in the center of the big lockring
     

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