Wheel bearing problems?

  • I have driven on the 997 VFL spacers with 14mm front and 18mm rear at 19inch. Had already been mounted by the previous owner (also registered). The last 1000 - 1500km the driving noise became louder and louder and I was first of the opinion, it is because of the "old" tires. But must have been the wheel bearings, because with another set of tires the noise was similar. Now are on the successor 997 FL these distances again on it, because I have kept the wheels with it. Question therefore, whether there are empirical values with this combi and the wheel bearings age particularly? So far they were actually relatively stable with Porsche. Thanks and greetings Axel

    This post has been automatically translated.

  • Good morning,


    I don't have any special experience with the wheel bearings on the 997.

    What I do know is that if I change the distance from the center of the rim to the bearing running plane, I also change the lever that acts on the bearing.

    In the case of inserted track plates, I increase the lever and thus the forces on the bearing. The geometry also changes, which should also result in greater forces.

    The wheel bearing has a service life that is calculated under normal conditions (series). With change, higher wear must be expected.

    Of course, I understand that for optical reasons it is seen with pleasure if the wheel arch is filled to the brim. Looks great, but is technically wrong.

    Porsche gives for my car in each case 5mm track plate free. That's probably the most acceptable change that keeps wear in check.

    I stick to it. ...but that is for everyone to decide for themselves.


    Greetings

    Michael

    This post has been automatically translated.

  • If you look at the dimensions of the wheel bearings used, you have to wonder why they last so long at all. The bearings are designed, the service life of rolling bearings can be calculated amazingly well based on the loads, but unfortunately no longer for fatigue strength ... the cost optimizers wielding the red pen have their fingers in everything. A slightly smaller wheel bearing costs just a few cents less ...


    The higher loads described by tribute due to the changed lever and force ratios are rather detrimental to the service life of the increasingly tightly designed parts.

    In turn, I would have to ask myself why the wheel bearings on my GT3 don't pulverize after just a few laps on the track...? The loads here are certainly much higher than on the road, especially with slicks or semislicks.


    So you can safely neglect the additional load due to track plates. Wheel bearings do not last forever and the change is only a medium operation.


    Greetz

    This post has been automatically translated.

    Nach 320'000 Spiegeleiern kann die Kantine nicht so schlecht gewesen sein!
    Harm Lagaay


    PS: Ich heisse nicht Greetz k:thinking:

  • Thank you both for the explanations! Confirms my gut feeling and will rebuild despite the now good optics times on front 7 and rear 14mm. Think that could be a good compromise. The wheel bearings I will keep an eye on ... In addition, another question: come slowly to the end or can there suddenly what crumble? Greetings Axel

    This post has been automatically translated.

  • 14mm in front is also a lot,

    that can also have a negative effect (rolling radius) on driving.

    affect.

    I have the GT 3 rims on it (997/2-4) and

    have front 5mm and rear 21mm.

    This post has been automatically translated.

    Gruß Wilfried


    Lieber unanständig jung bleiben, als anständig alt werden. :wink:


    997 4 FL 3,6L

  • Wheel bearings usually suffer pitting on the outer ring, the tread gets small material chipping like potholes. This then causes the noises that are initially audible when cornering on the left or right.

    Over time, these breakouts become larger and larger, and the noise is correspondingly more pronounced.


    If you dismantle a wheel bearing that has been making alarming noises, you will be amazed at how small the damage still is. Sometimes you still need a magnifying glass to find them...


    The horror of a breaking wheel bearing is extremely rare. I have seen something like that only once, on a Lotus Exige MK1, a lightweight construction. With Porsche such a bearing breakage is to be excluded, the bearings are massive enough.


    Greetz

    This post has been automatically translated.

    Nach 320'000 Spiegeleiern kann die Kantine nicht so schlecht gewesen sein!
    Harm Lagaay


    PS: Ich heisse nicht Greetz k:thinking:

  • Good evening "My name is not Greetz",


    I'm right there with you. Do you happen to know if the GT3 has the same wheel bearings as the C4? ... Bearing clearance, C.. ???


    Greetings

    "my name is Michael" :)

    This post has been automatically translated.

  • Yes, are the same.

    . Do you happen to know if the GT3 has the same wheel bearings as the C4? ...

    In 996 and 997 wheel bearings will always be an issue, if the first are still in it.

    The grease is just also >10years old.

    This post has been automatically translated.

  • The driving noise was already extreme. Think it was so about 50,000km, which were driven with the 14 and 18mm total. I now realize that these widths go on the bearings, but I'm still surprised how it affects. If you want the look, you should know that. Thanks again for your input! Greetings Axel

    This post has been automatically translated.

  • Hi Axel,

    You didn't write if you drive stock rims or accessories :pfeil: what is your total offset incl. discs?


    Greetings

    Al

    This post has been automatically translated.