News

Transfer case gears 308

Discussion in 'Technical Q&A' started by Gianluca, Feb 6, 2004.

  1. Gianluca

    Gianluca Formula Junior

    May 6, 2003
    349
    Centreville, Virgini
    Full Name:
    Gianluca Chegai
    Need some help.
    I am reassembling the 3 gears that need to come out during a clutch replacement. The top a bottom gears have the ring nuts that require a special tool.
    The bottom gear ring nut was torqued snugly but the top ring nut was totally slack. I could rock it back and foth with my fingers. The "locking tabs" were, however, engaged so the the nut could not have loosened by itself.
    It this correct? Should there be no torque on the top nut? If this is wrong, how much torque should I apply?
    Thanks.
     
  2. To remove this ad click here.

  3. atlantaman

    atlantaman Formula 3

    Mar 31, 2002
    1,726
    Roswell, Georgia
    Full Name:
    Charles
    no--they are both to be quite tight--you will need to check in the back of the service manual and the torques will be listed. Since ALL of the power has to go thru them--better not allow and movement.

    also be careful how you install the gears--the bottom one goes in backward from the way you would think--if i recall the longer sholder side goes OUT.And load up the gear oil on them before cranking---
     
  4. Steve Magnusson

    Steve Magnusson F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    19,348
    Texas
    Full Name:
    Steve Magnusson
    Page M6 in the 308GT4 WSM shows 20 Kg-m (144 ft-lb) for the M30 x 1.5P "Ring nut, clutch shaft" (and other similar-sized ring nuts in the gearbox are in the same torque ballpark).
     
  5. Mike328

    Mike328 F1 Rookie
    Rossa Subscribed

    Oct 19, 2002
    2,655
    Boulder, CO
    Full Name:
    Mike
  6. Birdman

    Birdman F1 Veteran

    Jun 20, 2003
    6,687
    North shore, MA
    Full Name:
    THE Birdman
    Please note that it is generally recommended to replace the ring nuts when you remove them. If one does come off and allows a gear to loosen, the resulting damage will cost you many thousands of dollars! (Ask me how I know!!!)
     
  7. To remove this ad click here.

  8. Gianluca

    Gianluca Formula Junior

    May 6, 2003
    349
    Centreville, Virgini
    Full Name:
    Gianluca Chegai
    Thank you all.
    Love this place!
     
  9. 4re gt4

    4re gt4 Formula 3

    Apr 23, 2002
    2,279
    Roseburg, OR
    Full Name:
    Hans E. Hansen
    I asked my mechanic if the ring nuts would need replacing. He said, "It depends upon who was in there last......."
     
  10. Birdman

    Birdman F1 Veteran

    Jun 20, 2003
    6,687
    North shore, MA
    Full Name:
    THE Birdman
    4re gt4, I agree. If the ring nuts (heh heh...he said "nuts"!) have been bent and re bent several times, I would replace them. If they are in pretty decent shape, they can probably be reused, but it is not recommended by Ferrari.

    The guy who had my car before me recycled a ring nut, which loosened and came off under load. The middle gear in the three gear set then came off and punched a hole in the transfer case cover. The transfer case cover was able to be repaired but the gear needed to be replaced by me when I got the car. The gears are only sold new in sets at $3,000 a set. I was lucky to get a perfect condition used gear for $600. Needless to say, the cost of a new ring nut is nothing (even at twenty something bucks that they get for them) compared with the cost of failure!!

    Now I have a killer Ferrari paperweight...a cracked transfer gear!

    Birdman
     

Share This Page