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512TR Hydraulic Clutch

Discussion in 'Technical Q&A' started by rjnavion, Dec 19, 2003.

  1. rjnavion

    rjnavion Karting

    Nov 1, 2003
    128
    Gate, OK (western O
    Full Name:
    Ron Judy
    I'm a relatively new owner of a '92 512TR and the clutch is not releasing all the way. Bleeding it helps for a few days and then the pedal is down again. Finally fluid leaked from the clutch housing, so probably the seals on the thrust bearing (throwout bearing) need replacing. From the Parts Catalog and the Workshop Manual I see that the fluid enters the clutch housing, passes into the bushing supporting flange, and into the thrust bearing to operate the fingers on the pressure plate. I am over 400 miles from Ferrari dealers in Denver and Dallas and the same distance from an independent Ferrari shop in Kansas City. My son and I both have auto and aircraft mechanic experience but are not Ferrari mechanics and don't want any surprises, so need suggestions from anyone who has done the repair or had similar clutch trouble.

    It appears the transmission oil and gearbox oil will have to be drained before pulling the clutch housing because of the output shaft into the gearbox and the pilot shaft between the gearbox and transmission. Is this correct? The Workshop Manual is very vague, just stating it is necessary to remove the muffler.

    I note that later serial numbers of 512TR's use a different thrust bearing with six seals instead of three like mine, and a different bushing supporting flange. Is my problem common enough to justify this change or would the cost be prohibitive?

    Any advice will be greatly appreciated. I love the car and want to get it on the road again. I had a major service with belts, new clutch disc and many more items recently but apparently these hydraulic seals weren't replaced.
     
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  3. jselevan

    jselevan Formula 3

    Nov 2, 2003
    1,856
    RJ - there is a great deal of experience on F-Chat. A few have posted their clutch change experience. Don't be discouraged that there has not been an answer in a few hours. If you ask it, they will come.

    Jim S.
     
  4. tbakowsky

    tbakowsky F1 World Champ
    Professional Ferrari Technician Consultant

    Sep 18, 2002
    15,277
    The Cold North
    Full Name:
    Tom
    Hi RJ...If your at all willing to try and do this your self it's really not that difficult of a job. You do have to drain the transfergear oil,but not the transoil. Really you only needs to drain about 1.5L. To remove the clutch housing you must remove the exahust. Not difficult just time consuming. As your doing the job stuff that needs to be removed will become apparent right away.

    The reseal of the slave and bearing assembly is very easy to do as well. Just make sure every thing is nice and clean during re-assembly. Before I slide everything back in place I put a small amount of brakefluid around the seals as a lubricant,so the seal don't twist when being installed in the slave shaft.
     
  5. Boxer12

    Boxer12 Formula 3

    Jun 1, 2003
    1,672
    RJ,
    You don't have to drain either. You will lose a little gear oil when you pull the bell housing off. You can get a slave cylinder rebuild kit and new bearing from TRutlands. See thread on '91 TR clutch replacement for detailed description and pics of job. Post any questions as you go.

    Jim
     
  6. rjnavion

    rjnavion Karting

    Nov 1, 2003
    128
    Gate, OK (western O
    Full Name:
    Ron Judy
    Thanks Jim S. for the encouragement and Tom and Jim A. for "hands on" experience in the clutch area. We definitely are going to tackle the job after Christmas is past. I removed pre-cats, test pipes, and muffler to install the Tubi muffler and it took myself and helper 1/2 day.

    Jim A., I've searched for the '91 TR Clutch Replacement thread to no avail. Tryed every imaginable wording in several forums and the archives; I'm missing something. I do need to read this.

    Is the thrust bearing replaced as a matter of principle or if it feels good, just replace the seals? At the major service and IRAN when a clutch disc was installed, the shop didn't mention the thrust bearing to me nor is a new one on the invoice. One thread concerning a '90 TR clutch reported a very high price for the Ferrari bearing but one owner in Australia was able to install a different bearing in the thrust bearing housing at much less cost. Anyone else have experience with this?

    Haven't heard from anyone concerning installing the later thrust bearing and carrier it slides on. Since my slave cylinder lasted 11 years and 20,000+ miles (unless there is history I'm unaware), I can accept this life span.

    Ron Judy
     
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  8. Boxer12

    Boxer12 Formula 3

    Jun 1, 2003
    1,672
     
  9. Boxer12

    Boxer12 Formula 3

    Jun 1, 2003
    1,672
    Ron, you can find the thread on www.fca.org, tech tips site, under mechanical topics, searching for "TR clutch."
     
  10. Boxer12

    Boxer12 Formula 3

    Jun 1, 2003
    1,672
    Ron,
    The T.O. bearing is replaced just because you might as well put the entire system inside bell housing back to OEM specs since you are taking the time to tear it apart. Same philosophy for the slave cylinder rebuild. You can use the old bearing as a doorstop like the rest of us :) The shaft that it sits on should be fine and I suspect it is a precast piece that would not be easy to find as new. Jim
     
  11. Ferrari_tech

    Ferrari_tech Formula 3

    Jul 28, 2003
    1,527
    UK
    Full Name:
    Malcolm W
    RJ,

    It shouldn't take you more than a day to complete the clutch seal replacement. Definately replace the bearing, all the seals and associated parts listed in the Ferrari update which I copy below.



    MW
     
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  13. WILLIAM H

    WILLIAM H Three Time F1 World Champ

    Nov 1, 2003
    34,891
    Victory Circle
    Full Name:
    HUBBSTER
    a good idea while you are in the neighborhood is to grab a piece of heat reflective material & cover the hose that takes the fluid to the clutch it is at the very end of the engine behind the clutch housing. Because of its location this hose tends to heat up & when the fluid boils your clutch becomes inoperative
     
  14. PSP

    PSP Formula Junior

    Mar 31, 2001
    603
    Lake Forest, CA USA
    Full Name:
    Patrick S. Perry
    That link is for the "Fellowship of Christian Athletes" - I assume you meant another link unless we are supposed to look for a license plate frame;)
     
  15. rjnavion

    rjnavion Karting

    Nov 1, 2003
    128
    Gate, OK (western O
    Full Name:
    Ron Judy
    Merry Christmas everyone!

    Thanks everyone for the posts and in help with my 512TR slave cylinder repair. I was especially glad to see Malcolm's (Ferrari_UK) scanning of the Ferrari Service Bulletin recommending replacement of the thrust bearing with the later version. It referred to the 1992 parts book. In the 1994 parts book there is third generation bearing that is available when the supply is exhausted but it requires changes of two other parts. The key to what I can do is what is available. I will contact Rutlands next week when the holidays have settled down and find what is available.

    I finally found Jim Avery's TR Clutch thread after first hitting on the Federation of Christian Athletes! You have to spell out the site. One thing I don't understand is Jim's problem removing the bearing from the sleeve assembly that is bolted to the housing. From the parts book it appears that the bearing must slide on this sleeve to activate the pressure plate. Another thing I don't see is which set of seals pertains to the slave cylinder. Is it the seals at each end of the thrust bearing or the two seals and two "O" rings on the back side of the sleeve assembly?

    I'm sure when I get it apart that all of this will be evident; I just want all the knowledge possible in hand before starting.

    Reference to insulating the fluid hose; my cats have been replaced with test pipes, the muffler with a tubi, and I plan to remove the innards of the pre-cats when I have them off, so my heat problem is much less than it was. I will monitor this close, though, and have access to a laser-type temperature monitor to check when hot weather arrives.

    When I have prices and what parts are available, I will post everything with parts numbers, etc. and give an account of how the job went.

    Ron Judy
     

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