Torque Specifications for Front Suspension Components | FerrariChat

Torque Specifications for Front Suspension Components

Discussion in '308/328' started by Brian A, Jan 16, 2020.

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  1. Brian A

    Brian A F1 Rookie

    Dec 21, 2012
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    1983 US 308 GTS QV
    #1 Brian A, Jan 16, 2020
    Last edited: Jan 16, 2020
    Torque specifications are listed in the 308QV/328 Workshop manual in table M6. However, several of the bolt descriptions unclear to me (a beginner) and some of the torque values are a surprise.

    Can someone provide the correct torque specs for the locations shown below?

    I will redo the below photo with the values and repost the photo with the hope that it will help others redoing their front suspension.

    A = Upper A arm and damper mount
    B = Upper and lower A arm mount
    C = Lower damper mount (correction: its part of D)
    D = Upper and Lower ball joints to A arms (are upper and lower different torque specs?)
    E = Upper ball joint to stub axle
    F = Lower ball joint to stub axle
    G = Wheel hub to stub axle
    H = Tie rod end to stub axle
    I = Sway bar link to stub axle
    J = Sway bar link to sway bar
    K = (not shown) Lower A arm mounting fork to frame (where the alignment shims go)
    L = Sway bar to frame
    M = Brake caliper to stub axle

    (Note that "C" is really part of "D". The damper is part of the lower ball joint connection. My mistake in creating the diagram.)

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  2. yelcab

    yelcab F1 World Champ
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    Nov 29, 2001
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    Mitchell Le
    From the 329 book, Suspension section

    A: 12mm, 56 Nm
    B: 12mm, same as A, 56 Nm
    C, don't know what that is
    D: 12mm, 70 Nm:
    E: 12mm, 70 Nm
    F: 12mm, 70 Nm
    G: 20mm, 160Nm
    H: 3/8 inch, 45 Nm
    I: 12mm, 60 Nm
    J: 12mm, 60 Nm
    There is no K
    L: 8mm, 21 Nm
    M: 12mm, 100 Nm, or 10mm with helicoil, 45 Nm
     
  3. johnk...

    johnk... F1 World Champ
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    For conversion, 1 Nm = 0.74 ft lb
     
  4. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
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    Brian Crall
    G specification is for a 328 NOT a 308. Do not torque your tapered roller bearings to the number or you WILL have a bearing failure in very short order.

    Caliper mounting on a 308 is very different than on a 328 and do not share the same specifications.

    Extreme care needs to be used in Ferrari torque specification tables. They are full of errors.
     
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  5. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
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    Brian Crall
    Read my post. You have just been given bad information.
     
  6. Brian A

    Brian A F1 Rookie

    Dec 21, 2012
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    Some of the translations are quite humorous too.

    My motive for posting actually was regarding G "Wheel hub to stub axle". On both front wheels this nut was basically just snug so I became alarmed.

    What IS the torque spec for G for a 308QV? For that matter, it would be much appreciated if you could review Mitch's numbers from the Workshop Manual and correct them to that for a 308QV.
     
  7. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
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    Brian Crall
    Torque for a nut on a tapered roller bearing?? Same as every other car using tapered rollers. And no, I do not believe I have ever seen a torque wrench in use professionally on a tapered roller wheel bearing. The 328 number you were given has no tapered roller bearings, hence the high number. .
     
  8. 2NA

    2NA F1 World Champ
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    Dec 29, 2006
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    Tim Keseluk
    Extremely good advice. Lots of wrong information , especially in the earlier books.
    160 Nm on that wheel bearing would be a BIG mistake.
     
  9. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
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    #9 Steve Magnusson, Jan 17, 2020
    Last edited: Jan 17, 2020
    That's essentially correct for an opposed tapered roller bearings arrangement. Ferrari even suggests leaving a little axial play when cold (and this is more important if you are really cooking the brakes which expands the hub) -- see page F8 of the 308GT4 WSM. IMO, you should at least be able to slide the thrust washer under the nut around a little from side-to-side using a screwdriver -- if you can't = it's too tight. Far better to use the 308GT4 WSM as a reference for 308QV suspension work (as the others have already said: "328 is a totally different design so doesn't apply").
     
  10. Brian A

    Brian A F1 Rookie

    Dec 21, 2012
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    1983 US 308 GTS QV
    As pledged, below is the photo showing torque specifications for the front suspension connections on a 308 QV. I am very glad to get these numbers. I worry that the natural tendency is to overtighten stuff and sanity-checking with a torque wrench is a very good thing.

    For the nut holding the wheel hub to the stub axle marked “G” in my original post, the torque spec in the 308QV/328 Workshop Manual for the 328 only. The 308 has opposing tapered roller bearings which requires a completely different tightening procedure than the 328. The correct tightening procedure for the 308 is described in detail in the GT4 Workshop Manual. The concept is to lightly tighten the nut against the bearing and then back off a little to allow for heat expansion. In the GT4 Workshop Manual, Ferrari specifies that the axial play should be 0.06 to 0.10 mm. They say that this is about 1/12 turn of the nut. Also see Steve Magnusson’s post within this thread. From other places, it looks like people back off the nut more than just 1/12 turn (more like ¼ turn plus). A new specialized nut should be used each time the bearing is staked/caulked. One side is right-hand thread and the other is left-hand thread. The nuts are expensive.

    The GT4 Workshop Manual is much more clearly written than the 308QV/328 manual. It is also published in various languages unlike the 308QV/328 manual which has 4 languages together in one book.

    Please correct any mistakes and misinterpretations I may have made. I am not a trained professional but I try to be methodical and careful in the work that I do.

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