Pilot bearing help | FerrariChat

Pilot bearing help

Discussion in '308/328' started by akimmel, Jul 28, 2013.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. akimmel

    akimmel Karting

    Aug 13, 2009
    189
    Dallas, TX
    Full Name:
    Art Kimmel
    #1 akimmel, Jul 28, 2013
    Last edited by a moderator: Sep 7, 2017
    Another dumb move on my part.
    I failed to measure the depth of the seat on the end of the crank for the pilot bearing. It's been years since I pulled all of this apart and I am wondering if it is proper for the bearing to not seat flush to the surface of the crank. It's about 0.140" out and I am reluctant to whale on it any harder than I already have. Pulling it probably means another new bearing so I thought I would ask if anyone in our forum knows.
    Thanks for any help! Picture attached.
    Art
    Image Unavailable, Please Login
     
  2. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,112
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    See the cross-section drawing on page D6 in the 308GT4 WSM -- some protrusion is present to center the flywheel (and there's some nominal clearance on the far side to the shoulder on the splined shaft). The ID hole in your flywheel may show some witness/rust marking from the old bearing being there -- if you account for the radius on the bearing outer race corner, it might give you an idea of the prior ballpark protrusion.
     
  3. akimmel

    akimmel Karting

    Aug 13, 2009
    189
    Dallas, TX
    Full Name:
    Art Kimmel
    The drawing makes me feel better about the protrusion. It's probably a good assumption that the drawing is somewhat to scale. The 0.14" that I measure is about 1/3 of the 0.4" measured flywheel thickness in that area. I'll leave the bearing for now and try to verify spline clearance when I attach the bell housing.
     
  4. smg2

    smg2 F1 World Champ
    Sponsor

    Apr 1, 2004
    15,502
    Dumpster Fire #31
    Full Name:
    SMG
    Steve's right, the outer race is used as a concentric center for the flywheel. typical protrusion is ~0.150"
     

Share This Page