How to Adjust Tightness of Front Wheel Bearings on a 308 | FerrariChat

How to Adjust Tightness of Front Wheel Bearings on a 308

Discussion in '308/328' started by Brian A, May 23, 2020.

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  1. Brian A

    Brian A F1 Rookie

    Dec 21, 2012
    3,086
    SanFrancisco BayArea
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    1983 US 308 GTS QV
    #1 Brian A, May 23, 2020
    When I grasp the top of my front tire and push the wheel in and out, I can feel a little bit of movement and can hear the rollers sliding on the bearing race.

    I recently replaced my front wheel bearings and worry now that the races were not fully seated when I adjusted the tightness and now have excessive looseness. However, I don’t know what is acceptable.

    Should there be this movement? How much is tolerable?
     
  2. thorn

    thorn F1 Rookie
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    Aug 7, 2012
    3,322
    Tallahassee, FL
    #2 thorn, May 23, 2020
    Tapered bearings require a preload. Assuming the bearings were seated correctly, torque the bearing nut to 18 lbs. Then loosen, retorque to 11 ft/lbs. Then lock the nut.

    Axial play should be a minimum (or exactly) .06 mm. Maximum play is .1 mm
     
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  3. Martin308GTB

    Martin308GTB F1 Rookie

    Jan 22, 2003
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    Martin N.
    #3 Martin308GTB, May 23, 2020
    Hi John,

    there is a slight discepancy. If there's preload there won't be any play. I adjust mine by torquening the nut to 18 lbs, and then loosen it till I can slide the washer below with the help of a screwdriver.
    A -tiny- bit of tactile movement of the wheel is o.k. And the WSM spec of max. 0.1mm bearing play IS perceptible when grasping and wiggling the wheel on its outer edge. I prefer that over a preloaded bearing, but I would worry about hearing the rollers on a new bearing.

    Best from Germany
    Martin
     
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  4. thorn

    thorn F1 Rookie
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    #4 thorn, May 23, 2020
    My instincts tell me we're approaching the final result the same way. To be honest, I didn't even measure the play after installing new bearings and double-torqueing. I'm sure that will send me to technician Hell, but so be it.
     
  5. Brian A

    Brian A F1 Rookie

    Dec 21, 2012
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    #5 Brian A, May 24, 2020
    It is interesting that you apply a torque to the bearing (i.e. leave no play). Its good to know that this is doesn't cause problems.

    I had originally followed the GT4 Workshop Manual directions to leave that play that Martin cites. If I recall correctly, I believe the manual says appropriate play is adjusted by backing the nut off 1/12 turn (half a flat). That is how I did it anyway.

    My mistake was not ensuring the races were fully seated. If I were to change the bearings again (which probably won't happen in my lifetime), I would tighten the nut down fully and rotate the wheel a dozen times, tighten again if necessary and rotate some more. This would seat the races. Only then would I set the play. … and the Workshop Manual may actually say to do this. Live and learn.

    It sounds like I should readjust my front wheel bearings. This time I will use the "jiggle the washer with a screwdriver" technique. I may try reusing the nuts as I expect tightening will give me room to "rekey" the nuts with new metal.
     
  6. thorn

    thorn F1 Rookie
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    #6 thorn, May 24, 2020
    Brian - doublecheck me on that. I could not find the bearing method in a 308QV manual (god, I hate those PDF scans... can NEVER find what I'm looking for), so I was going by various notes I've collected over the year from other owners' posts.

    The "back off 1/2 turn" method is certainly done on some cars, so make sure you pick the correct procedure. Martin may be correct, and me in error; he certainly knows far more about bearings than I do.
     
  7. Brian A

    Brian A F1 Rookie

    Dec 21, 2012
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    1983 US 308 GTS QV
    #7 Brian A, May 24, 2020
    Attached is the salient page from the GT4 Workshop Manual. There is no description of adjusting QV front wheel bearings in the 308QV/328 Workshop Manual.

    Image Unavailable, Please Login
     
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