The ISO 2768 only applies to the following drawings with the subsequent features. It is used when these functions do not have custom tolerance indications individually:

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If whoever replaced the CV joint didn't properly torque the axle nut, hammered the crap out of the axle to get it out, or allowed weight onto the bearing before the nut was torqued, the CV job could have caused the bearing to fail.

few days later hooked up the flatbed trailer to it to go pick up a non-running motorcycle only 25 miles away - truck had not been moved since i got home from the long trip, mind you - made the trip over, picked up the bike, started home - bearing failure so bad it had to be put on the trailer to make it the last 10 miles home - it no longer wanted to move, and the wheel was sitting at an odd angle.

How to check forbadwheelbearing

Tolerances are generally controlled by ISO 2768 standard. ISO 2768 tolerancing is based on the size of the feature. Small feature sizes have closer tolerances and large features feature sizes have larger tolerances.

There are four classes of size tolerances: fine(f), medium(m), coarse(c) and very coarse(v). For example, a company that manufactures precision parts and equipments might select the medium(m) for general metric tolerances. This is given by ISO 2768-m, the tolerances for various dimensions will be given by the general metric tolerance table.

From IT6 to IT18, the standard tolerances are multiplied by the factor 10 at each fifth step. This rule applies to all standard tolerances and may be used to extrapolate values for IT grades not given in Table 1. For example, the nominal size range 180 mm up to and including 250 mm, the value of IT20 is:

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On the Dodge Ram pickup however - when that one started making noise, it only lasted about 60 miles before it wanted to seize up, and the wheel was wobbling...was not a pretty sight at all.

Various features such as chamfers, fillets, rounds, hole depths, and thread lengths, can be dimensioned with single limits. The abbreviation for minimum (MIN) or maximum (MAX) follows the dimension value to specify a single limit application. The unspecified limit is 0 when MAX is used or reaches infinity when MIN is specified. For example, R6MIN means the minimum radius should be 6mm or RMAX6 means the maximum radius can be 6mm.

2) Does a $585 estimate by the independent garage for parts and labor for replacing the front hub and wheel bearings sound right to you? The dealer quoted $550 parts and labor for just the bearing replacement; an additional $176 for the hub parts if those are necessary, and an additional $294 labor plus more $$$ in parts for the housing if that's necessary.

How to tell which wheelbearingisbadwhile driving

Reference dimensions are defined by using parenthesis around the dimension or using the term “REF” or “Ref.” behind the dimension. For example, (10.5) or 10.5 REF or 10.5 Ref.

1) A service rep at our local Subaru dealer claimed driving on the bad bearing longer could cause damage to the hub and housing, resulting in a more costly repair. True or not? Who is right - the dealer or the good reliable indie garage mechanic? Note that however many parts need to be replaced or whatever the labor, the dealer costs 2x as much as our very capable independent garage.

Theoretically Exact Dimensions (TED) or Theoretically Exact Measures (TEM), are also called Basic Dimensions. TED are given from a datum to a feature of interest. TED are defined as a numerical value to describe the theoretically exact size, profile, or location of a feature. Variations allowed to these dimensions are based on feature controls, notes, or tolerance of other dimensions. No tolerance is specified explicitly to TED.

Whoever does the job should have the hub in hand in case it's needed. If there are any signs the inner race has been spinning on the hub, the hub must be replaced.

The wrr-wrr-wrr-wrr-wrr sound my wife and I heard when driving on curves over 25-30 mph when curving right and left, uphill or downhill, powered or unpowered, which seemed to be coming from the front of the car, was caused by a bad wheel bearing, apparently the Left Front. It could be entirely unrelated, but it happened not long after replacing the axle after the R Front CV boot blew open after it was hit hard by some road debris on the highway + wheels aligned.

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A unilateral tolerance varies in only one direction from the specified dimension. For example, 10.5 +0.2/-0 or 10.5 +0/-0.1.

Ignoring tolerance will add to challenges in assembly and increase cost significantly. Here are our ideas if you need to reduce these challenges.

International Standard ISO 2768:1989 was prepared by Technical Committee ISO/TC3, Limits, and fits, it comes in two parts, namely ISO 2768-1 and ISO 2768-2.

heartless, do you mean check the center of the outside tire tread (which will be warm anyway) or the center of tire around the hub?

When you reach out to check - assume the wheel center will be hot and use caution accordingly - if it isnt hot, you are good. barely luke warm is ok, but would be thinking about it pretty soon - the hotter it is, the worse shape it is in.

Our very good independent garage mechanic recommended about a month or two ago to drive on it a little longer, so that we could be 100% sure which wheel the noise is coming from. Seems clear right now it's the Left Front. He said it wouldn't cause any further harm driving on it longer. It is getting progressively louder to the point where we can hear extra noise in the background even when driving straight.

Approximate dimensions are used when the tolerances are not very important. They are indicated by using the term “APPROX.” before or after the dimensional value. They are often indicated using “ca.” or “~”. There is no supervision or measurement of approximate dimensions. For example, 10.5 APPROX. could be any value close to 10.5mm.

1995 Dadge Ram 1500 (shortbox with a topper on it) - made a 600 mile trip, towing a trailer, drop the trailer off 30 mins from home. on the way home noticed a very slight growly noise...told the other half about it, he looked into what it would cost to get a new hub (easier) for it...never ordered it tho...

A bilateral tolerance is allowed to vary in two directions from the specified dimension. For example, 10.5(+0.2/-0.1) is an unequal bilateral tolerance and the dimension 10.5±0.2 is called an equal bilateral tolerance.

Bad things can happen, but this really can't happen with this car. It can get very loose and wobble and pretty much chew the axle right into the bearing races and the housing, expensive and possible loss of control, so something to be avoided, but as you grind to a halt the wheel will still be attached.

Running a bad wheel bearing will run the risk of damaging not only the hub, but the brake rotor, caliper, ABS tone ring and ABS sensor.

If the wheel bearing is noisy but tight the chances for damaging the hub or the housing are low, in my opinion. If you drive on it and it gets loose and you don't notice, those other parts might take some damage. If there is any damage the hub will be the item damaged, most likely, you would have to do some really extreme stuff to damage the housing.

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Reference dimensions are used to provide information or visualization only. Reference dimensions are often used as additional information to accumulation of other dimensions or to show a dimension that is defined elsewhere with tolerance. No tolerance is defined explicitly for a reference dimension and no inspection is necessary.

Theoretically Exact Dimensions are used to prevent accumulation of tolerance. Chain dimensioning using Tolerance-based Dimensions can cause accumulation of tolerance as the tolerances of all chain dimensions would add up.

Tolerance defines the acceptable range of variation allowed on a dimension. It helps to define criticality in the part and ensure assembly.

IT grade(s) describe an internationally accepted code system that categorizes the linear tolerances into 12 categories. This allows Product Owners and Data Scientists to handle tolerances with a single number. The system is defined in ISO 286 and frequently used.

Getting hot is the deal breaker. Have i ever seen a subaru loose a wheel because of a bad bearing ,no . Have i seen it in dozens of other cars, yes.

My last one chewed up the hub/spindle and discolored some metal from heat. Oh, it also wobbled a little and that tire had more uneven wear than the others.

Yep - could go at any time. And it will destroy a lot of expensive parts if it completely fails. ABS parts and the hub for certain. Probably brake components as well. Wheel could come off.... but that is less likely.

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The standard ISO 286 defines the system of tolerances, deviations, and fits only for basic sizes up to 3150 mm. However, IT grades can be extrapolated in the following way.

center of the wheel - where the axle nut would be - and/or, between the center cap and lug nuts - any heat created from friction in the wheel bearing will transfer out to the wheels in as little as 5-10 miles if they are getting bad enough

On mine it was indeed difficult to isolate the bad bearing, had to spin each wheel with a mechanics stethoscope on the strut spring.

My '03 LL bean left-front wheel bearing failed at 75k? 80K? 100K? I forget (thread is here somewhere) and I drove on it a looooong time with it making noise. It never got loose, never got hot, hub and housing were fine. Of course if it got loose I would probably notice and so I would drive on it longer than I'd be willing to let my wife.

If you are certain of which one it is, next time you drive it somewhere, when you stop, check the center of the wheel with your hand - carefully - is it hot? or is it cool to the touch? if it is cool, you should be fine for a while yet.

The relation between two mating parts due to the difference between their sizes before the assembly, is defined as fits.

The system considers both the nominal size as well as the tolerance width to determine a proxy for the “manufacturing complexity”

Standardized prefixes include the letters A, B, C, CD, D, E, EF, F, G, H, J, JS, K, M, N, P, R, S, T, U, V, X, Y, Z, ZA, ZB, ZC (for holes), and the lower-case equivalents (for shafts). All of these letters represent some kind of distribution around the nominal value. H and h are easiest to explain as the tolerance lies entirely on one side of the nominal size.

I drove on my bad bearing for several months with no ill effects, other than the noise getting louder and more annoying..

Deviation is plus-minus dimensioning. It uses a bilateral or unilateral tolerance format, depending on the application. Plus-minus dimension values are placed using the plus-minus symbol (±). For example, 10.5±0.2 or 0.250±0.005.

Limit tolerance is an alternative method of showing and calculating tolerance. With limit dimensioning, the extreme values of the tolerance are given in the dimension. The limits are upper limit and the lower limit.

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For example, here the tolerances of dimension 25, 10 and 15 will add up to define position of the ø10 hole, resulting in a higher tolerance band. This can be avoided using theoretically exact dimensions.

Based on an experience with my WRX, I'd say wheelbearings are only gonna last a few days at best after they get loud and 'crunchy' sounding. I dunno how long they could 'whir', I had the A/C on high last summer, and the radio!

had a guy tell me he drove a hummer that had 500k miles on i with a bad wheel bearing thousands of miles till it caught on fire! ahaha:Flame:

The upper limit is the largest the feature can be within the given tolerance of the dimension. The lower limit is the smallest the feature can be within the given tolerance of the dimension.

YMMV, but I have driven thousands of miles on noisy wheel bearings. But most of our driving is around town. If I were doing mostly hway driving, then I would get them replaced sooner rather than later. If local driving, do it at your leisure within a few months. just my .02

as far as cost - where you live has a lot to do with that - silicon vally, you might be right in line - i had a rear bearing done on my wagon that only cost me about $250 - BUT - I live in northern Wisconsin - major difference.

I was in the same situation and kept driving until it was real bad, Like someone else said it damaged the hub which added $150 to the cost of the job. The inner race spun on the hub and wore a grove in it and ruined it. Do it now or the repair will just get more expensive

IT grades do not specify how the tolerance limits are distributed around the nominal value, IT grades with an alternate prefix are used for this purpose. For example, the prefix ‘js’ is used in place of ‘IT’ to specify the symmetrical distribution, so a dimension 12 js5 is equivalent to 12±0.004 (where 12 IT7 is 0.008).

Last time I checked, a new ABS sensor was almost $200 from the dealer. A new hub is in the neighborhood of $130 and so on. I've had customers that had other shops tell them it was ok to run it a bit longer but what people don't tell you is when it will finally grenade. As a mechanic, I don't have a crystal ball that tells me when it's going to break so I always tell the customer, the sooner you do it, the better it is for your peace of mind and your vehicle.