can front wheel bearings be damaged

On Dec 6, 1:24*pm, N8N > wrote:
> On Dec 6, 12:29*pm, "John S." > wrote:
>
>
>
>
>
> > On Nov 30, 5:17*pm, N8N > wrote:
>
> > > ...by mounting or rotating tires? *I don't see how, BUT keep reading.
>
> > > At my last oil change, I got new tires installed on my company car. *I
> > > immediately noticed an increase in road noise, but chalked it up to
> > > the different tread of the new tires (Uniroyal Tiger Paw vs. Goodyear
> > > Integrity) and since the old, OEM tires were so awful, I figured it
> > > was a small price to pay for actual traction.
>
> > > I just got an oil change again last week, about 7K miles later. *I
> > > asked that the tires be rotated and balanced while there because the
> > > car is a notorious tire eater ('08 Impala.) *When I got the car back
> > > the mechanic said that I should take the car to the dealership and see
> > > if they would warranty the front wheel bearings because both felt
> > > loose, and he said that typically one should see no perceptible play
> > > in them. *I ASSume that these are not the tapered rollers that I know
> > > and love but are one piece cartridge bearings so no adjustment is
> > > possible. *I had to take the car to the dealer anyway to get a
> > > malfunctioning door lock fixed (fleet people wouldn't let regular
> > > garage fix it for reasons unknown to me...) and they replaced both
> > > front wheel bearings under warranty and immediately I noticed a
> > > reduction in road noise.
>
> > > Now, I can't think of a mechanism by which simply undoing and redoing
> > > the lugs would cause a wheel bearing to fail... right?
>
> > > I suppose it is possible that they just went bad right about that
> > > time... I remember I had one get really loud on the last Imp that I
> > > had but that was maybe 20K miles later (60K vs. 40K miles) funny thing
> > > was that not three days after I had it replaced I hit a very large and
> > > deep pothole at speed and trashed it *again* - wow, they're not real
> > > strong are they? *(I saw the pothole but thought it was a patch so
> > > didn't swerve around it) but anyway, it just seems odd to me that they
> > > would both go bad exactly as I had the tires replaced...
>
> > > nate
>
> > I don't see how a mechanic could damage the wheel bearings
> > unintentionally. *I think that by replacing worn noisy hard riding
> > used tires with soft riding quiet new tires that the sound of grinding
> > bearings was no longer buried in ambient noise and became more
> > apparent.
>
> > Anyone who thinks that a car can hit a very large and deep pothole and
> > not damage something is probably not the most reliable source of
> > information anyway.
>
> ??? *I grew up in western PA. *Hitting large and deep potholes is a
> daily occurrance there, or at least was in the 70's and 80's. *Most of
> the time you could avoid them, but sometimes there were just so damn
> many of them that you couldn't avoid hitting one or two.
>
> nate- Hide quoted text -
>
> - Show quoted text -

Re-read the OP. He hit a very large and deep pothole at speed.
Granted, for him at speed might be 5 mph and the pothole might be 2" x
1/4", but probably all the numbers are much higher.

On 12/06/2010 10:13 AM, Brent wrote:
> On 2010-12-06, jim > wrote:
>> On 12/06/2010 06:27 AM, Brent wrote:
>>> On 2010-12-06, jim > wrote:
>>>
>>> <attempted cover up of ignorance deleted>
>>>
>>>>> If you can't rotate, as per a FWD car that more heavily wears the
>>>>> front you must always replace all four tires to avoid having more worn
>>>>> tires on the rear. So it's back to what I wrote initially thanks for
>>>>> playing.
>>>
>>>> wow.
>>>
>>> You've clearly been weak in logic and continue to be. Your
>>> recommendations are logically incompatible. Read the quoted portion from
>>> BMW again, it says 'do not move tires from one axle to the other'.
>>
>> but /why/ brent? what is the reason they say this? that is the
>> question you're simply not addressing. there /is/ a very good reason,
>> and it's /not/ wear. what is it?
>
> You're not dealing with the logical problem of your argument. nice try.

on the contrary. you need to man up to the question brent. /you/ are
the one avoiding it.


>
> Thanks for playing, don't forget your copy of the home game.
>
>>> That
>>> means you cannot move tires from the rear to the front. That's the 'no
>>> rotate' source you specified. Do not move from one axle to the other. It
>>> doesn't say, don't move accept when buying two new tires, it says don't
>>> move the tires.
>>>
>>> Combined with avoiding a condition of having more worn tires on the
>>> rear the logical implication is that if front tires are worn all four
>>> must be replaced. Which is what I stated in the first place, replace all
>>> four for best results.
>>>
>>> Thanks for playing, maybe you'll get the home version of this game on
>>> your way out.
>>>
>>>
>>
>>
>>
>>


--
nomina rutrum rutrum

On 12/06/2010 10:09 AM, Brent wrote:
> On 2010-12-06, jim > wrote:
>> On 12/06/2010 06:18 AM, Brent wrote:
>>> On 2010-12-06, jim > wrote:
>>>> On 12/05/2010 01:45 PM, Brent wrote:
>>>>> On 2010-12-05, jim > wrote:
>>>>>
>>>>>>>> no, applied load is independent of "suspension geometry". you're either
>>>>>>>> making an attempt at a red herring, or proving significant
>>>>>>>
>>>>>>> You're asking for the load applied to the bearing by giving the loads on
>>>>>>> the TIRE.
>>>>>>
>>>>>> get a grip - if you're not applying the load via the tire, you're
>>>>>> airborne.
>>>>>
>>>>> I'll give you one more clue: a tire isn't a rigid body and beam
>>>>> equations.
>>>>
>>>> when are you going to do the math for us then brent? i set you up with
>>>> a nice simple example - show us how you think it's done.
>>>
>>> Ok, Using only the information you provided, the tire, and the whole
>>> suspension has to be assumed to be a rigid body while accepting the
>>> obvious error that one bearing type can be swapped for the other without
>>> changing the design. This means no calculations are required
>>
>> ???
>>
>>
>>> and the
>>> force components on the bearings of all four wheels are the forces you
>>> gave.
>>
>> it's not. and i wasn't looking at "all four wheels", just the loading
>> on a single bearing [since that is what we were discussing] with the
>> vectors stated.
>>
>> the 1000kgf load is vertical.
>
> 2200 lbs on one tire..

it could be 10,000kgf or 100kgf. doesn't matter to the vector angle -
where this bearing stuff came from.


>
>> with 0.6g lateral loading added [the bit
>> where the vectors come in], you get 600kgf of horizontal. that gives
>> you the force vector triangle, and thus it's simple trig to determine
>> that the /resultant/ vector load is 1166kgf at 31.0� from vertical.
>> i'll let you relate that to the capacities of the two bearings cited -
>> both load and angle.
>
> You're even a bigger idiot, actually something beyond that because I
> already explained fixturing to you. Your "/resultant/ vector load"
> being applied to the bearing is the height of stupidity. Let me ASCII
> sketch for you.
>
> TIRE TIRE
> W W
> H HUBorKnkl H knuckle
> E-OB--IB VS E--WB
> L HUBorKnkl L Knuckle
> L L
> TIRE TIRE
> ^<-- ^<--
> | |
>
> OB=outer tapered bearing IB=Inner tapered bearing, WB=double row ball
> bearing.

brent, the bearing has absolutely no idea what it's attached to. all it
knows is the load, and what direction it's coming from. the "fixture"
is completely irrelevant, as per the math as outlined above.


>
> Can you figure it out now? I know I showed you web drawings before but
> you probably didn't bother to look. Draw your reaction forces. Even with
> the rest of your assinine assumptions where you ignore the spring force
> from the suspension, the tire behaving like a spring, the force from
> the dampener (shock absorber/strut), the suspension bushings acting
> like torsional springs,

this is a red herring, but i can't resist: "suspension bushings acting
like torsional springs"??? what kind of load do you think they exert?
what percentage is it of the primary load???


> and much more.
>
> Here, try and understand support conditions:
> http://en.wikipedia.org/wiki/Beam_%28structure%29
> http://www.clag.org.uk/beam.html#key
> http://www.roymech.co.uk/Useful_Tabl...r_Bending.html

but brent, you were the one who said loading was a function of vectors
[actually the most accurate statement you've made]. but then you said
that loading was a function of machining tolerances [bizarre]. here you
are saying it's a function of beam deflection [even more bizarre].
you're badly confused.


>
> Then again you can't even address why tapered roller bearings have been
> successfully used as wheel bearings for decades and still are used in
> the heavy duty applications.

buses use tapered rollers. how many g's do you think a bus experiences
when cornering? what would be the vector angle resultant? how does
that compare to a vw [golf/rabbit] gti that uses angular ball bearings
and the lateral force i cited earlier?


>
>>> If you want it at each wheel, you then have to make the
>>> unrealistic assumption that each tire has the same grip and the car
>>> itself is rigid (the later isn't too bad) and divide by 4. See how easy
>>> it when you're ignorant?
>
>> no, it's not "divide by 4".
>
> You're the one putting 2200lbs on a single wheel with no elaboration as
> to how it got loaded that way.

doesn't matter to the trig brent.


>
>> given the above, i think elaboration is pointless.
>
> It's been pointless for me to elaborate for some time because you
> refuse to understand systems,

"systems" is math brent. you don't have any.


> instead you want to part swap and neglect
> many other factors to arrive at fantasy result that supports your
> blathering. Trouble is, fantasy results are only good in your imginary
> world.
>
>
>


--
nomina rutrum rutrum

On 2010-12-06, jim beam > wrote:
> On 12/06/2010 10:13 AM, Brent wrote:
>> On 2010-12-06, jim > wrote:
>>> On 12/06/2010 06:27 AM, Brent wrote:
>>>> On 2010-12-06, jim > wrote:
>>>>
>>>> <attempted cover up of ignorance deleted>
>>>>
>>>>>> If you can't rotate, as per a FWD car that more heavily wears the
>>>>>> front you must always replace all four tires to avoid having more worn
>>>>>> tires on the rear. So it's back to what I wrote initially thanks for
>>>>>> playing.
>>>>
>>>>> wow.
>>>>
>>>> You've clearly been weak in logic and continue to be. Your
>>>> recommendations are logically incompatible. Read the quoted portion from
>>>> BMW again, it says 'do not move tires from one axle to the other'.
>>>
>>> but /why/ brent? what is the reason they say this? that is the
>>> question you're simply not addressing. there /is/ a very good reason,
>>> and it's /not/ wear. what is it?
>>
>> You're not dealing with the logical problem of your argument. nice try.

> on the contrary. you need to man up to the question brent. /you/ are
> the one avoiding it.

You're just trying to deflect your ignorance, again.

Perhaps you should explain how four indentical new wheels and tires
become different without wear or damage being involved. Remember, BMW
states that even when all wheels and tires are the same size... Or are
you going to suggest that a moron may damage something in the process of
rotating?

But even if you can do that, you're still left with a huge logical
problem. If you follow a no-rotation recomendation you can't pull off a
2 new tires, keep the least worn tires on the rear program when the
fronts wear faster.

Don't go away mad, just go away.

>> Thanks for playing, don't forget your copy of the home game.
>>
>>>> That
>>>> means you cannot move tires from the rear to the front. That's the 'no
>>>> rotate' source you specified. Do not move from one axle to the other. It
>>>> doesn't say, don't move accept when buying two new tires, it says don't
>>>> move the tires.
>>>>
>>>> Combined with avoiding a condition of having more worn tires on the
>>>> rear the logical implication is that if front tires are worn all four
>>>> must be replaced. Which is what I stated in the first place, replace all
>>>> four for best results.
>>>>
>>>> Thanks for playing, maybe you'll get the home version of this game on
>>>> your way out.
>>>>
>>>>
>>>
>>>
>>>
>>>
>
>

On 2010-12-06, jim beam > wrote:
> On 12/06/2010 10:09 AM, Brent wrote:
>> On 2010-12-06, jim > wrote:
>>> On 12/06/2010 06:18 AM, Brent wrote:
>>>> On 2010-12-06, jim > wrote:
>>>>> On 12/05/2010 01:45 PM, Brent wrote:
>>>>>> On 2010-12-05, jim > wrote:
>>>>>>
>>>>>>>>> no, applied load is independent of "suspension geometry". you're either
>>>>>>>>> making an attempt at a red herring, or proving significant
>>>>>>>>
>>>>>>>> You're asking for the load applied to the bearing by giving the loads on
>>>>>>>> the TIRE.
>>>>>>>
>>>>>>> get a grip - if you're not applying the load via the tire, you're
>>>>>>> airborne.
>>>>>>
>>>>>> I'll give you one more clue: a tire isn't a rigid body and beam
>>>>>> equations.
>>>>>
>>>>> when are you going to do the math for us then brent? i set you up with
>>>>> a nice simple example - show us how you think it's done.
>>>>
>>>> Ok, Using only the information you provided, the tire, and the whole
>>>> suspension has to be assumed to be a rigid body while accepting the
>>>> obvious error that one bearing type can be swapped for the other without
>>>> changing the design. This means no calculations are required
>>>
>>> ???
>>>
>>>
>>>> and the
>>>> force components on the bearings of all four wheels are the forces you
>>>> gave.
>>>
>>> it's not. and i wasn't looking at "all four wheels", just the loading
>>> on a single bearing [since that is what we were discussing] with the
>>> vectors stated.
>>>
>>> the 1000kgf load is vertical.
>>
>> 2200 lbs on one tire..
>
> it could be 10,000kgf or 100kgf. doesn't matter to the vector angle -
> where this bearing stuff came from.

Vector angle? Trying to sound clever, but your underlying ignorance
continues to be demonstrated. Here's a hint, vectors have direction, so
vector angle is redundant.

>>> with 0.6g lateral loading added [the bit
>>> where the vectors come in], you get 600kgf of horizontal. that gives
>>> you the force vector triangle, and thus it's simple trig to determine
>>> that the /resultant/ vector load is 1166kgf at 31.0? from vertical.
>>> i'll let you relate that to the capacities of the two bearings cited -
>>> both load and angle.

>> You're even a bigger idiot, actually something beyond that because I
>> already explained fixturing to you. Your "/resultant/ vector load"
>> being applied to the bearing is the height of stupidity. Let me ASCII
>> sketch for you.
>>
>> TIRE TIRE
>> W W
>> H HUBorKnkl H knuckle
>> E-OB--IB VS E--WB
>> L HUBorKnkl L Knuckle
>> L L
>> TIRE TIRE
>> ^<-- ^<--
>> | |
>>
>> OB=outer tapered bearing IB=Inner tapered bearing, WB=double row ball
>> bearing.
>
> brent, the bearing has absolutely no idea what it's attached to. all it
> knows is the load, and what direction it's coming from. the "fixture"
> is completely irrelevant, as per the math as outlined above.

Yep. Total ignorance. Total willful ignorance. Go study support types,
degrees of freedom, etc.

Buh-bye.

On 12/06/2010 11:11 AM, John S. wrote:
> On Dec 6, 1:24�pm, > wrote:
>> On Dec 6, 12:29�pm, "John > wrote:
>>
>>
>>
>>
>>
>>> On Nov 30, 5:17�pm, > wrote:
>>
>>>> ...by mounting or rotating tires? �I don't see how, BUT keep reading.
>>
>>>> At my last oil change, I got new tires installed on my company car. �I
>>>> immediately noticed an increase in road noise, but chalked it up to
>>>> the different tread of the new tires (Uniroyal Tiger Paw vs. Goodyear
>>>> Integrity) and since the old, OEM tires were so awful, I figured it
>>>> was a small price to pay for actual traction.
>>
>>>> I just got an oil change again last week, about 7K miles later. �I
>>>> asked that the tires be rotated and balanced while there because the
>>>> car is a notorious tire eater ('08 Impala.) �When I got the car back
>>>> the mechanic said that I should take the car to the dealership and see
>>>> if they would warranty the front wheel bearings because both felt
>>>> loose, and he said that typically one should see no perceptible play
>>>> in them. �I ASSume that these are not the tapered rollers that I know
>>>> and love but are one piece cartridge bearings so no adjustment is
>>>> possible. �I had to take the car to the dealer anyway to get a
>>>> malfunctioning door lock fixed (fleet people wouldn't let regular
>>>> garage fix it for reasons unknown to me...) and they replaced both
>>>> front wheel bearings under warranty and immediately I noticed a
>>>> reduction in road noise.
>>
>>>> Now, I can't think of a mechanism by which simply undoing and redoing
>>>> the lugs would cause a wheel bearing to fail... right?
>>
>>>> I suppose it is possible that they just went bad right about that
>>>> time... I remember I had one get really loud on the last Imp that I
>>>> had but that was maybe 20K miles later (60K vs. 40K miles) funny thing
>>>> was that not three days after I had it replaced I hit a very large and
>>>> deep pothole at speed and trashed it *again* - wow, they're not real
>>>> strong are they? �(I saw the pothole but thought it was a patch so
>>>> didn't swerve around it) but anyway, it just seems odd to me that they
>>>> would both go bad exactly as I had the tires replaced...
>>
>>>> nate
>>
>>> I don't see how a mechanic could damage the wheel bearings
>>> unintentionally. �I think that by replacing worn noisy hard riding
>>> used tires with soft riding quiet new tires that the sound of grinding
>>> bearings was no longer buried in ambient noise and became more
>>> apparent.
>>
>>> Anyone who thinks that a car can hit a very large and deep pothole and
>>> not damage something is probably not the most reliable source of
>>> information anyway.
>>
>> ??? �I grew up in western PA. �Hitting large and deep potholes is a
>> daily occurrance there, or at least was in the 70's and 80's. �Most of
>> the time you could avoid them, but sometimes there were just so damn
>> many of them that you couldn't avoid hitting one or two.
>>
>> nate- Hide quoted text -
>>
>> - Show quoted text -
>
> Re-read the OP. He hit a very large and deep pothole at speed.
> Granted, for him at speed might be 5 mph and the pothole might be 2" x
> 1/4", but probably all the numbers are much higher.

he /is/ the op.

and while it's highly unlikely and only really possible if the bearing
is either defective or badly under-spec, it /is/ technically possible to
brinell a bearing like this. if the bump is within the range of
suspension travel, load would not be high enough to do it, but if the
suspension and tire had bottomed, then you could get a high load
transient several times the normal running load, and a low spec or low
hardness bearing could brinell at that point. much like bearings
commonly brinell when being abused by techs with hammers.


--
nomina rutrum rutrum

On 12/06/2010 11:25 AM, Brent wrote:
> On 2010-12-06, jim > wrote:
>> On 12/06/2010 10:13 AM, Brent wrote:
>>> On 2010-12-06, jim > wrote:
>>>> On 12/06/2010 06:27 AM, Brent wrote:
>>>>> On 2010-12-06, jim > wrote:
>>>>>
>>>>> <attempted cover up of ignorance deleted>
>>>>>
>>>>>>> If you can't rotate, as per a FWD car that more heavily wears the
>>>>>>> front you must always replace all four tires to avoid having more worn
>>>>>>> tires on the rear. So it's back to what I wrote initially thanks for
>>>>>>> playing.
>>>>>
>>>>>> wow.
>>>>>
>>>>> You've clearly been weak in logic and continue to be. Your
>>>>> recommendations are logically incompatible. Read the quoted portion from
>>>>> BMW again, it says 'do not move tires from one axle to the other'.
>>>>
>>>> but /why/ brent? what is the reason they say this? that is the
>>>> question you're simply not addressing. there /is/ a very good reason,
>>>> and it's /not/ wear. what is it?
>>>
>>> You're not dealing with the logical problem of your argument. nice try.
>
>> on the contrary. you need to man up to the question brent. /you/ are
>> the one avoiding it.
>
> You're just trying to deflect your ignorance, again.
>
> Perhaps you should explain how four indentical new wheels and tires
> become different without wear or damage being involved. Remember, BMW
> states that even when all wheels and tires are the same size... Or are
> you going to suggest that a moron may damage something in the process of
> rotating?
>
> But even if you can do that, you're still left with a huge logical
> problem. If you follow a no-rotation recomendation you can't pull off a
> 2 new tires, keep the least worn tires on the rear program when the
> fronts wear faster.
>
> Don't go away mad, just go away.

the no-rotation directive is for a very solid technical reason. you
need to go back in this thread and re-read it.


>
>>> Thanks for playing, don't forget your copy of the home game.
>>>
>>>>> That
>>>>> means you cannot move tires from the rear to the front. That's the 'no
>>>>> rotate' source you specified. Do not move from one axle to the other. It
>>>>> doesn't say, don't move accept when buying two new tires, it says don't
>>>>> move the tires.
>>>>>
>>>>> Combined with avoiding a condition of having more worn tires on the
>>>>> rear the logical implication is that if front tires are worn all four
>>>>> must be replaced. Which is what I stated in the first place, replace all
>>>>> four for best results.
>>>>>
>>>>> Thanks for playing, maybe you'll get the home version of this game on
>>>>> your way out.
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>>
>>
>>


--
nomina rutrum rutrum

On 12/06/2010 11:26 AM, Brent wrote:
> On 2010-12-06, jim > wrote:
>> On 12/06/2010 10:09 AM, Brent wrote:
>>> On 2010-12-06, jim > wrote:
>>>> On 12/06/2010 06:18 AM, Brent wrote:
>>>>> On 2010-12-06, jim > wrote:
>>>>>> On 12/05/2010 01:45 PM, Brent wrote:
>>>>>>> On 2010-12-05, jim > wrote:
>>>>>>>
>>>>>>>>>> no, applied load is independent of "suspension geometry". you're either
>>>>>>>>>> making an attempt at a red herring, or proving significant
>>>>>>>>>
>>>>>>>>> You're asking for the load applied to the bearing by giving the loads on
>>>>>>>>> the TIRE.
>>>>>>>>
>>>>>>>> get a grip - if you're not applying the load via the tire, you're
>>>>>>>> airborne.
>>>>>>>
>>>>>>> I'll give you one more clue: a tire isn't a rigid body and beam
>>>>>>> equations.
>>>>>>
>>>>>> when are you going to do the math for us then brent? i set you up with
>>>>>> a nice simple example - show us how you think it's done.
>>>>>
>>>>> Ok, Using only the information you provided, the tire, and the whole
>>>>> suspension has to be assumed to be a rigid body while accepting the
>>>>> obvious error that one bearing type can be swapped for the other without
>>>>> changing the design. This means no calculations are required
>>>>
>>>> ???
>>>>
>>>>
>>>>> and the
>>>>> force components on the bearings of all four wheels are the forces you
>>>>> gave.
>>>>
>>>> it's not. and i wasn't looking at "all four wheels", just the loading
>>>> on a single bearing [since that is what we were discussing] with the
>>>> vectors stated.
>>>>
>>>> the 1000kgf load is vertical.
>>>
>>> 2200 lbs on one tire..
>>
>> it could be 10,000kgf or 100kgf. doesn't matter to the vector angle -
>> where this bearing stuff came from.
>
> Vector angle? Trying to sound clever,

they're /your/ words brent!


> but your underlying ignorance
> continues to be demonstrated. Here's a hint, vectors have direction, so
> vector angle is redundant.

"vector angle is redundant"????????????????


>
>>>> with 0.6g lateral loading added [the bit
>>>> where the vectors come in], you get 600kgf of horizontal. that gives
>>>> you the force vector triangle, and thus it's simple trig to determine
>>>> that the /resultant/ vector load is 1166kgf at 31.0? from vertical.
>>>> i'll let you relate that to the capacities of the two bearings cited -
>>>> both load and angle.
>
>>> You're even a bigger idiot, actually something beyond that because I
>>> already explained fixturing to you. Your "/resultant/ vector load"
>>> being applied to the bearing is the height of stupidity. Let me ASCII
>>> sketch for you.
>>>
>>> TIRE TIRE
>>> W W
>>> H HUBorKnkl H knuckle
>>> E-OB--IB VS E--WB
>>> L HUBorKnkl L Knuckle
>>> L L
>>> TIRE TIRE
>>> ^<-- ^<--
>>> | |
>>>
>>> OB=outer tapered bearing IB=Inner tapered bearing, WB=double row ball
>>> bearing.
>>
>> brent, the bearing has absolutely no idea what it's attached to. all it
>> knows is the load, and what direction it's coming from. the "fixture"
>> is completely irrelevant, as per the math as outlined above.
>
> Yep. Total ignorance. Total willful ignorance. Go study support types,

how does a bearing know what's supporting it brent?


> degrees of freedom, etc.

how does a bearing know what degrees of freedom a steering knuckle has
brent?

you need to go study remedial math. seriously - your teachers failed
you BADLY.


>
> Buh-bye.
>
>


--
nomina rutrum rutrum

On Dec 6, 2:11*pm, "John S." > wrote:
> On Dec 6, 1:24*pm, N8N > wrote:
>
>
>
>
>
> > On Dec 6, 12:29*pm, "John S." > wrote:
>
> > > On Nov 30, 5:17*pm, N8N > wrote:
>
> > > > ...by mounting or rotating tires? *I don't see how, BUT keep reading.
>
> > > > At my last oil change, I got new tires installed on my company car. *I
> > > > immediately noticed an increase in road noise, but chalked it up to
> > > > the different tread of the new tires (Uniroyal Tiger Paw vs. Goodyear
> > > > Integrity) and since the old, OEM tires were so awful, I figured it
> > > > was a small price to pay for actual traction.
>
> > > > I just got an oil change again last week, about 7K miles later. *I
> > > > asked that the tires be rotated and balanced while there because the
> > > > car is a notorious tire eater ('08 Impala.) *When I got the car back
> > > > the mechanic said that I should take the car to the dealership and see
> > > > if they would warranty the front wheel bearings because both felt
> > > > loose, and he said that typically one should see no perceptible play
> > > > in them. *I ASSume that these are not the tapered rollers that I know
> > > > and love but are one piece cartridge bearings so no adjustment is
> > > > possible. *I had to take the car to the dealer anyway to get a
> > > > malfunctioning door lock fixed (fleet people wouldn't let regular
> > > > garage fix it for reasons unknown to me...) and they replaced both
> > > > front wheel bearings under warranty and immediately I noticed a
> > > > reduction in road noise.
>
> > > > Now, I can't think of a mechanism by which simply undoing and redoing
> > > > the lugs would cause a wheel bearing to fail... right?
>
> > > > I suppose it is possible that they just went bad right about that
> > > > time... I remember I had one get really loud on the last Imp that I
> > > > had but that was maybe 20K miles later (60K vs. 40K miles) funny thing
> > > > was that not three days after I had it replaced I hit a very large and
> > > > deep pothole at speed and trashed it *again* - wow, they're not real
> > > > strong are they? *(I saw the pothole but thought it was a patch so
> > > > didn't swerve around it) but anyway, it just seems odd to me that they
> > > > would both go bad exactly as I had the tires replaced...
>
> > > > nate
>
> > > I don't see how a mechanic could damage the wheel bearings
> > > unintentionally. *I think that by replacing worn noisy hard riding
> > > used tires with soft riding quiet new tires that the sound of grinding
> > > bearings was no longer buried in ambient noise and became more
> > > apparent.
>
> > > Anyone who thinks that a car can hit a very large and deep pothole and
> > > not damage something is probably not the most reliable source of
> > > information anyway.
>
> > ??? *I grew up in western PA. *Hitting large and deep potholes is a
> > daily occurrance there, or at least was in the 70's and 80's. *Most of
> > the time you could avoid them, but sometimes there were just so damn
> > many of them that you couldn't avoid hitting one or two.
>
> > nate- Hide quoted text -
>
> > - Show quoted text -
>
> Re-read the OP. *He hit a very large and deep pothole at speed.
> Granted, for him at speed might be 5 mph and the pothole might be 2" x
> 1/4", but probably all the numbers are much higher.

Um, I *am* the OP.

nate

On Dec 6, 2:29*pm, jim beam > wrote:
> On 12/06/2010 11:11 AM, John S. wrote:
>
>
>
>
>
> > On Dec 6, 1:24 pm, > *wrote:
> >> On Dec 6, 12:29 pm, "John > *wrote:
>
> >>> On Nov 30, 5:17 pm, > *wrote:
>
> >>>> ...by mounting or rotating tires? I don't see how, BUT keep reading.
>
> >>>> At my last oil change, I got new tires installed on my company car. I
> >>>> immediately noticed an increase in road noise, but chalked it up to
> >>>> the different tread of the new tires (Uniroyal Tiger Paw vs. Goodyear
> >>>> Integrity) and since the old, OEM tires were so awful, I figured it
> >>>> was a small price to pay for actual traction.
>
> >>>> I just got an oil change again last week, about 7K miles later. I
> >>>> asked that the tires be rotated and balanced while there because the
> >>>> car is a notorious tire eater ('08 Impala.) When I got the car back
> >>>> the mechanic said that I should take the car to the dealership and see
> >>>> if they would warranty the front wheel bearings because both felt
> >>>> loose, and he said that typically one should see no perceptible play
> >>>> in them. I ASSume that these are not the tapered rollers that I know
> >>>> and love but are one piece cartridge bearings so no adjustment is
> >>>> possible. I had to take the car to the dealer anyway to get a
> >>>> malfunctioning door lock fixed (fleet people wouldn't let regular
> >>>> garage fix it for reasons unknown to me...) and they replaced both
> >>>> front wheel bearings under warranty and immediately I noticed a
> >>>> reduction in road noise.
>
> >>>> Now, I can't think of a mechanism by which simply undoing and redoing
> >>>> the lugs would cause a wheel bearing to fail... right?
>
> >>>> I suppose it is possible that they just went bad right about that
> >>>> time... I remember I had one get really loud on the last Imp that I
> >>>> had but that was maybe 20K miles later (60K vs. 40K miles) funny thing
> >>>> was that not three days after I had it replaced I hit a very large and
> >>>> deep pothole at speed and trashed it *again* - wow, they're not real
> >>>> strong are they? (I saw the pothole but thought it was a patch so
> >>>> didn't swerve around it) but anyway, it just seems odd to me that they
> >>>> would both go bad exactly as I had the tires replaced...
>
> >>>> nate
>
> >>> I don't see how a mechanic could damage the wheel bearings
> >>> unintentionally. I think that by replacing worn noisy hard riding
> >>> used tires with soft riding quiet new tires that the sound of grinding
> >>> bearings was no longer buried in ambient noise and became more
> >>> apparent.
>
> >>> Anyone who thinks that a car can hit a very large and deep pothole and
> >>> not damage something is probably not the most reliable source of
> >>> information anyway.
>
> >> ??? I grew up in western PA. Hitting large and deep potholes is a
> >> daily occurrance there, or at least was in the 70's and 80's. Most of
> >> the time you could avoid them, but sometimes there were just so damn
> >> many of them that you couldn't avoid hitting one or two.
>
> >> nate- Hide quoted text -
>
> >> - Show quoted text -
>
> > Re-read the OP. *He hit a very large and deep pothole at speed.
> > Granted, for him at speed might be 5 mph and the pothole might be 2" x
> > 1/4", but probably all the numbers are much higher.
>
> he /is/ the op.
>
> and while it's highly unlikely and only really possible if the bearing
> is either defective or badly under-spec, it /is/ technically possible to
> brinell a bearing like this. *if the bump is within the range of
> suspension travel, load would not be high enough to do it, but if the
> suspension and tire had bottomed, then you could get a high load
> transient several times the normal running load, and a low spec or low
> hardness bearing could brinell at that point. *much like bearings
> commonly brinell when being abused by techs with hammers.

It might have bottomed, the suspension on the car is stupid soft, but
I kind of doubt it seeing as I was doing about 55-60 MPH at the time
(onramp.) On the flip side, it was the LF wheel that hit the hole, so
that side was more loaded than normal at the time.

I just don't remember having these kind of issues with the cars my
parents drove, which typically only got the bearings packed/replaced
when the brakes were done, and the brake service intervals for those
cars tended to be very long as my parents were typically not
aggressive drivers and the family cars were usually stickshifts. Upon
reflection, since the late 80's their regular daily use car was a VW
Golf which also had cartridge-type front wheel bearings, and if they
were ever replaced on that car, I don't remember it. I do recall
having a bad *rear* wheel bearing on that car, which were traditional
tapered rollers, but those seem to have been undersized for the
application as I also had problems with them on my own '84 GTI as well
and have heard the same from others.

nate