Trick to bolt the 348 subframe back in? | FerrariChat

Trick to bolt the 348 subframe back in?

Discussion in 'Technical Q&A' started by PassionIsFerrari, Jan 18, 2007.

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  1. PassionIsFerrari

    PassionIsFerrari Formula 3

    Aug 15, 2004
    2,454
    I've had to move the car while I was fixing the timing belt issue on my 348. Anyway, when I fought with bolting the subframe on the left and right sides where you have 6 bolts on each side that secure the subframe to the frame... Is there a trick that makes these bolts go in easier...It literally took me a half day of fighting per bolt to get them to screw in...

    It seems to me like the rounded edges of those bolts makes it more difficult because just flop around instead of catching the threads...

    Whats the trick?????

    Thanks..
     
  2. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    37,121
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    Brian Crall
    Undamaged threads and proper hole alignment. If you have those they will screw in with your fingers.
     
  3. chaa

    chaa F1 Veteran

    Mar 21, 2003
    5,058
    Is the 348 engine and subframe similar to that of a 355?? I put in the TOP pair of suspension subframe mount bolts each side. Also along with the two pairs each side SIDE mounting bolts in first. Then i put in the two sets of 6 bolts on the rear of the subframe that mounts to the body.
    I did it this way because the easyer top and side bolts aligned the 12 at the rear perfectly. If for ant reason the rear two set of 6 bolts dont align up, this has to be either up or down alignment, but this can be remedied by a jack. Also a round tapered pry bar was at hand.
    Anyways i dont know if this is the same system that is used on the 348 but there ya go
     
  4. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    37,121
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    Brian Crall
    It is very similar.
     
  5. PassionIsFerrari

    PassionIsFerrari Formula 3

    Aug 15, 2004
    2,454
    Was the car angled...or level...or will this affect anything...I hand screwed each bolt without the subframe and they go in very easy, but I was doing it to attach the actual sub-frame, it was very difficult...

    Did you use the prybar for left and right alignment?
     
  6. chaa

    chaa F1 Veteran

    Mar 21, 2003
    5,058
    #6 chaa, Jan 18, 2007
    Last edited by a moderator: Sep 7, 2017
    It was done from the floor mate. The unit was on a trolley so as the car lowered every thing was level. Then because of lack of room between the floor and body i put on the bottom 3 on each side because the top ones were pigs to get at. Then i tightened them up and jacked up the car and put in the final upper 3 on each side and bingo! I never needed the pry bay but i had it. Did you put in the top and side bolts in first, or did you just go straight for the rear 12??
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  7. 2NA

    2NA F1 World Champ
    Consultant Owner Professional Ferrari Technician

    Dec 29, 2006
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    Tim Keseluk
    A little planning (a set of thread chasers is always handy) and a patient approach to getting everything lined up should do it.
     
  8. spider348

    spider348 Formula 3

    Nov 3, 2003
    1,273
    MA
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    John
    I purchased a tap and die to clean both threads prior to assembly. If the bolts came out with little tension there must be an alignment issue. If everything is not square, parallel and level the bolts will bind in the holes. Good Luck!
     
  9. PassionIsFerrari

    PassionIsFerrari Formula 3

    Aug 15, 2004
    2,454
    i put the top and side and the bolts on top on the shock towers as well...I tried to use a jack that was half on the subframe and half on the frame so that both would be square...didn't work...then just used the jacks on the frame to raise and lower but I think my problem was sideways alignment...thats why I asked if you had to use the pry bar....
     
  10. 2NA

    2NA F1 World Champ
    Consultant Owner Professional Ferrari Technician

    Dec 29, 2006
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    Tim Keseluk
    Thread chasers aren't taps or dies. They will clean and straighten threads and are a "must have" in a well equipped shop. Using a tap or die to clean up threaded holes and fasteners is risky, you could end up with a cross-thread or worse.
     
  11. tbakowsky

    tbakowsky F1 World Champ
    Consultant Professional Ferrari Technician

    Sep 18, 2002
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    The Cold North
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    Yes sometimes you have to use MINIMAL prying pressure to get the bolts started in the front section of the subframe. Use of a floor jack to help is usually needed. Leave everything loose including the 4 large bolts at the rear of the car and the shock tower nuts as well. This will help big time. Then go around and tighten everything up.
     
  12. rivee

    rivee F1 Rookie

    Jan 20, 2002
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    John
    What's a thread chaser?
     
  13. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    29,064
    socal

    YUP! Fingers are all I need. I do it the easy way. I have a full service lift and lift the car off the subasembly on a home made set of blocks to match the rake of the chassis. Then when done I lower the car right back down and just screw the bolts right back in. Maybe your car was hit and nothing lines up?
     

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