can front wheel bearings be damaged

...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

Reply to
N8N
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If for some reason they hit the hubs with a big hammer then maybe... otherwise I can't see how changing the tires would do it. Perhaps the different tire noise made the bearing noise more noticible?

I am guessing that the impala has ball bearings in the front? The problem with ball bearings is they can't take much lateral load. Tapered roller bearings are superior as they are designed to take lateral and radial loads.

As to play, it should be zero. Mazda (FWD cars I am most familiar with) has a spec of 0.5mm of play max. My experience is they can get noisy and still have no measurable play.

Reply to
Brent

On the web,

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2008 Chevrolet Impala front wheel bearings problems cuhulin

Reply to
cuhulin

if you're in the rust belt, maybe they hammer the wheels to break them free if they don't come off on their own? that'll brinell the bearings quite successfully. oh, and they're likely cheap chinese bearings since it's g.m, so no longevity there.

Reply to
jim beam

not true. most fwd cars use double row angular contact ball bearings - they most definitely are designed for and can take substantial lateral load.

they can take higher loads for a given size, but they have no tolerance for loads outside their normal config - in that regard, ball bearings are more tolerant, hence their use on fronts where there's all kinds of stuff going on.

Reply to
jim beam

No, me either. The mechanic felt the looseness and this was confirmed by the noise you got with the new tires.. I'm going to vote that the new tires amplified the need for the new bearings but had nothing to do with them being worn.

Reply to
hls

It is for typical ball bearings.

compared to regular ball bearings, but nothing like what a roller can handle.

What do you mean "outside their normal config"? Using parts as they aren't supposed to be used can result in failure. Tapered roller bearings did the job on front ends for years, it's just about cost. There are even sealed double row tapered roller bearings.

Reply to
Brent

what is a "typical" ball bearing? single row? double row? 15 ° angular contact? 30° angular contact? full compliment? there's a /lot/ more to this than you seem to be considering.

again, you're not considering any of the other factors. rollers are great for a narrow range of angular loads - the rollers need to be loaded evenly long their length, not just one end. if they're loaded outside of that, they don't roll evenly and all kinds of issues occur. now, you can load them outside of that range if the loading is light, but then your bearing ends up being overkill.

they're to be used for their specified loading angle which is very narrow. see above.

nope. nothing gives a greater range of load angle tolerance than double row angular ball. that's why they're used.

yes there are, but that's irrelevant to the above.

Reply to
jim beam

A typical ball bearing, an inner race, a cage and an outer race. No special angles or bullshit, just a ball bearing as found in all sorts of things, from the very small to the rather large. Here:

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shouldn't need to spell this out so I wonder if you're just playing games.

Now you're just being a usenet nit picker. You're not going to get that kind of uneven loading in any fixtureed environment. If you're loading through only part of the cup or cone to get the uneven loading you are describing you've done a shitty design and/or the shaft in the inner race isn't concentric with the bearing mount holding the outer race. The races shouldn't be loaded like that in any kind of bearing except those designed to have the inner race rotate relative to the outer.

Anyway for a situation like a wheel bearing, that's what the proper preload is for. To keep the outer race from tilting and loading the rollers improperly. Also there is a distance between inner and outer wheel bearings to prevent them from being loaded at some odd angle. This costs money. It's not some bearing you can just press in at one end like the double row angular ball bearings.

Again, this doesn't apply to a fixtured environment.

This is a fixtured environment, what variety of load angles are you going to be dealing with? You've got primarily a radial load and some axial load... The vector breaks down into those two components at the bearing(s). There isn't some point load at some angle being applied to some location on the OD or ID. If there was that's not the intended usage and something is very wrong. This whole concept of "load angle tolerance" seems rather foreign and sounds to me to be tolerance of shaft and housing not being concentric. Since a wheel bearing is a cantilevered set up the inner and outer races and what is mounted on them will always be concentric unless the bearing(s) is(are) damaged.

Anyway, here:

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Click on the figure that shows the contact angle. See how the ball is held in place? The races are formed to resist axial loading. Now take a look at a cross section of a tapered roller bearing.
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See how much more capability there is to take axial load? Now look at a typical, ordinary, garden variety ball bearing, see link above... hardly anything for axial load. If what you mean is that angular ball bearings are easier to deal with in an assembly enviroment because they are more tolerant of things not being concentric, not needing a preload, etc and so forth, then yes they are more tolerant. More tolerant of the wallet becaus making things more precise costs money. Those are cost motivations. Is it nice that angular ball bearings can be made assemble and forget? yes. But there's a trade off for that and that is in the loads they can survive. The inner/outer tapered roller bearing set up is simply stronger, more supportive and can take more axial load than a double row angular ball bearing at one end of the hub.

BTW:

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Notice what they call a typical ball bearing.

Reply to
Brent

you mean single row, deep groove, conrad.

of course you are - that's why ball bearings are more commonly used, because of their misalignment tolerance.

nope, it's a practical reality. i don't know what kind of tolerance you think you're getting on the average steering knuckle [for instance], but it sure ain't the sub-micron tolerance you're getting on the bearing.

dude, you can't /not/ have them misaligned to some extent. at least, not with any loading that causes elasticity [which is by definition inevitable], and without spectacular precision in the machining of the parts to which they're fitted.

no, the fitting on both is identical.

you don't understand what that really means. see above.

you're badly confused. it's too simplistic to be really useful, but some of the concepts you need to understand are here:

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no dude. see above. and you need to understand the nature of elasticity and loading - you cannot have one without the other.

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no dude, you're confused. those angles you're looking at are for the angle of the roller taper, they're nothing to do with loading.

we've already discussed this - yes, rollers can take more radial load, but they /cannot/ take more axial load. it causes the roller to pinch at one end, roll eccentrically, then wear to a barrel shape. this may not worry some manufacturers who can't get past the 1950's designs where they didn't know this stuff, but that's not reason to remain in ignorance.

single row, deep groove, conrad. if someone's asking you a technical question, give a technical answer!

Reply to
jim beam

It is clear you don't understand the geometeries involved or the designs. Ball bearings are used because they are CHEAP and EASY to install in a manufacturing envirionment. Your angular ball bearings are tolerant of the cheap design. If you use tapered roller bearings correctly you get a much more robust design that is also much more expensive, if for nothing else the cost of the bearings.

Now it's really clear you have no understanding. Make the steering knuckle hole or spindle off by an inch location wise, hell make it 15 degrees off angle wise too while you're at it, what's in the inner race of the bearing is still concentric with the outer race of the bearing within the tolerance of the bearing. The bearing is fixtured in the knuckle the hub is fixtured in the bearing. Or the bearings are fixtured on the spindle and the hub is fixtured on the bearings. There's nothing on the other side of the wheel that's not concentric creating a load because it's only fixtured on one side.

The only way you can get off centered is with a spindle (or knuckle hole) that that has two sections that aren't concentric with an inner/outer wheel bearing design. This requires actually being monumentally stupid and doing the machining in two steps with re-fixturing of the workpiece in between to create such error. Only an idiot would allow such a thing. The entire spindle (or knuckle hole) will be machined with the part fixtured once.

Spindles with inner and outer tapered roller bearings were manufactured successfully for decades without the benefit of modern CNC machine tools. The spindle is a machined shaft. Making a machined shaft with both ends concentric is not rocket science. Neither is making a bore that has both ends concentric. I'll tell you right now the outer side of that steering knuckle bore that holds an angular contact ball bearing is sufficently concentric with the inside part of it that you can put tapered roller bearings on both sides of it and have proper loading and alignment. The reason? You couldn't press in your angular contact ball bearing (easily and without damaging it) if it wasn't concentric. If the hole was wavy or stepped the bearing would jam upon being pressed in.

Dude, you have ONE FIXED END. They will ALWAYS be concentric within the tolerance of the bearing. There is no other fixed end to cause a misalignment. Machining concentric shafts and straight holes is not "spectacular precision". You couldn't even get your angular ball bearing in the hole if it wasn't straight. The concentricity of the assembly between the hub's bearing mounting and the knuckle/spindle's bearing mounting is completely driven by the bearing. There's no other end to be off center to create a load.

Now if you're going to argue that where the wheel is mounted is off center from the end that's mounted to the bearing, you're back at being cheap ass again and no matter how tolerant of said misaligment your bearing is the car is going to go thump-thump down the road.

If you cannot understand basic tolerancing there's no point in continuing. I'm not even going to bother reading the rest. three strikes.

Reply to
Brent

  1. there's not a significant difference in cost.

  1. "cheap design" is not loading that can be inside a 40°+ arc.

  2. you're still not getting it on /why/ tapered rollers only have a small angle of application.

uh, i don't know how you drive, but when i drive, i go around corners. when i go around corners, the loading axis on my wheels changes. hence the bearings get loaded "off axis". if you can't understand that, this conversation hasn't gone anywhere.

see above. you need to understand the basics before you start talking about anything else.

it's ironic that you try to talk of "tolerancing", yet don't seem to understand the fundamentals of load application. without that, "tolerancing" is utterly irrelevant.

Reply to
jim beam

It's not just the cost of the bearing itself. But the machining and and assembly. I was VERY clear about that. Plus there are TWO bearing assemblies in the tapered roller bearing design. Also looking at retail cost is irrelevant compared to what manufacturers pay.

Define this and describe why it is meaningful to a wheel bearing set up that has been done properly with a bearing that can withstand both axial and radial loading.

Whatever wierd ass loading you're using to make a usenet point simply does not apply. Bearings are fixtured to control the loads that they see. If you aren't going to use a bearing correctly then all bets are off. What it seems you want to do is take a single tapered roller bearing, press it into a knuckle and then press the hub into the the bearing just like is done with the ball bearings. This is not the way to use them, they aren't designed to be used that way. And yes, if used that way they will fail because they aren't fixtured properly and thus will see wierd ass loads outside their design. The races will indeed pivot relative to each other and not distribute the load on the rollers correctly. But, if used correctly, in a design so made, they won't see those loads, only the axial and radial components as they are designed to handle.

It's a cheap way to assemble so what is used instead is the angular contact ball bearings so the cheap machining, cheap assembly, and cheaper bearings can be used. To use the tapered roller bearings which can withstand higher loads as you admitted, the design is different and more expensive. I keep repeating that. You must use bearings correctly. You're comparing an incorrect use of tapered rollers to a correct use of angular ball.

I refer you to two posts ago where I told you that at the bearing the load is broken down into two vectors. Axial and radial load. That's what the bearing sees because it sits in a fixtured environment. It doesn't care about the loading axis at the tire. It sees what that vector breaks down into. That's why bearings are rated for their axial and radial loads and not rated for every degree from zero to 360.

Also Tapered roller bearings were used for DECADES succesfully with much poorer manufacturing tolerances than today's. They were used properly. Your argument comes down to a usenet irrelevance of taking a design for an angular contact ball bearing and shoving a tapered roller bearing in it. That's irrelevant. Bearings need to be fixtured according to their design. When you put together a _proper_ tapered wheel bearing design you'll have something that is _more expensive_ than a proper angular ball bearing design. The tapered roller design will be able to withstand higher loads.

Now it's very clear you want to shove a tapered roller into a angular ball design. YOU CANNOT DO THAT. The entire design has to properly fixture the bearing(s).

Now you're just doing declarations. Clearly you're out of your league here. And I spelled it correctly so I don't know what your problem is. It seems that you simply lack the knowledge of how to do more than one design. You're thinking parts swapping. You made that clear with your idiotic comparison of retail bearing prices. You don't even grasp how a tapered roller bearing design is different.

Here is the angular ball type:

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Here is tapered roller:
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See the difference?

Here's tapered roller as a single press on piece, notice the proportions of hub and mounting.

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Are you also noting that heavier vehicles are still using tapered roller? Why do you think that might be?

Why would a truck or a 4x4 off road vehicle want to use tapered roller bearings if what you say was the least bit true?

Reply to
Brent

While whiskey head and the paranoid guy circle jerk, poor Nate doesn't get his questions answered. I'll do it. No, tire rotation won't affect your bearings. Maybe if you put on a square tire. That's stupid, and so is rotating tires. If tires are wearing unevenly, address the alignment problem. If a bearing goes bad, replace the bearing.

Only time to switch around tires is when replacing. When the fronts are worn too much on a FWD Impala, throw them away, put the rears on the front, and new tires on the rear. Simple as all get out.

Any wear problem on Impala fronts is caused by poor alignment. Have alignment done by by somebody who knows how to do it right. Rear alignment on some Impalas is impossible because they are screwed from the factory, and destroy rear tires. Luck of the draw. If you have a rear wear problem, get the spindle rod kit. Google Impala GM bulletin CSP-08032. That fixes that. You can whine about GM, or just fix the problems and get on with your life.

Problems solved, so I'm off to do other good deeds.

Reply to
Bob Cooper

Actually, it was my answer to Nate that "whiskey head" objected to. As far as paranoid is concerned, I suggest you look at true paranoia put on display for us via the TSA.

That was my answer.

FWD cars often more heavily wear the front tires for obvious reasons of the relative work done and weight distribution.

It is best to keep all four tires the same. better tires on the rear is second best. But Nate already understands that sort of thing.

Reply to
Brent

Whiskey head has never added anything valuable to the group. His rants, volatile nature, and lack of understanding about things mechanical long ago put him in my killfile.

Reply to
hls

ok, let's stop right here. if you think there's a difference in the machining for a shaft with a deep groove ball bearing fitted and the machining on a shaft with a tapered roller fitted, you have problems way beyond anything i can address.

Reply to
jim beam

no it's not.

  1. rotation causes traction loss since it's taking a tire /out/ of a position to which it has become "fitted". the chalk board test is quick, cheap, and easily shows how the contact patch area becomes reduced because of it.
  2. rear tires have to cut the tightest arc, thus experience the highest lateral forces, and therefore require more lateral grip. you should correspondingly keep better tires on the rear. [a hard concept for some people to understand, but that's not because they've not been given the facts.]

if he does, that would make one of you.

Reply to
jim beam

you seem to be paying an extraordinary amount of attention to someone you're not paying attention to...

Reply to
jim beam

It's pretty clear that you are totally clueless. You don't even understand the basic assembly, vector sums, or anything else. You even show your greater stupidity directly above with astoundingly weak and ignorant attempt to create a strawman. If I thought you had even the slightest ability to understand I'd bother attempting to explain it to you, but it's pretty clear you don't.

Reply to
Brent

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