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...

4. Axial impeller force The blades of the impeller creates a thrust on the axle making it want to go forward, much in the same way the blades on a propeller on a boat or an airplane makes the vehicle go forward. When an angled propeller blade spins, it pushes water or air behind it. Newton’s third law of motion states that for every action, there is an opposite and equal reaction – so when air or water is pushed backwards, a reaction force in the opposite direction, a thrust, is created which causes the boat or airplane to move forward. Of course the industrial fan is locked down and doesn’t have wheels on it so it remains stationary, but the thrust still creates a reaction force in the form of an axial load on the bearings.

If you are interested in a bearing's lifetime in terms of number of revolutions rather than in terms of operational hours, the L10-formula (rather than the L10h-formula) is used.

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.

1. Assembly weight The full weight of the components in the image are held up by the two bearing assemblies. The force of the weight points perpendicularly to the axle, therefore the load acts radially on the bearings. Here’s the formula for this load:

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.

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!

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.

In a back-to-back arrangement, the load lines diverge along the bearing axis. Axial loads acting in both directions can be accommodated, but only by one bearing or bearing set in each direction. Bearings mounted back-to-back provide a relatively rigid bearing arrangement. The wide span between bearing effective centres makes this arrangement particularly well suited to support moment loads.

Bearing arrangement back to backcalculator

In a face-to-face arrangement, the load lines converge along the bearing axis. Axial loads acting in both directions can be accommodated, but only by one bearing or bearing set in each direction. The shorter span between effective bearing centres makes face-to-face arrangements less suitable to support moment loads compared to bearings in a back-to-back arrangement.

Try different bearings by inputting their different C-values and n-values to the L10-formula (along with the values calculated for P, and p) until you reach a value that his higher than and as close as possible to the desired L10h-value you selected in step 4.1.

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

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:

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

Bearingarrangements pdf

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.

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.

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.

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.

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?

The L10 life is the number of revolutions or hours that 90% of identical bearings will last. (In other words, 10% of identical bearings in a given group are not expected to achieve the L10 life.)

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.

The value for the Dynamic load rating (C) and the value for Rotational speed (n) is listed by the manufacturer or the designer.

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

2. Belt tension The belt between the two belt pulleys must not be loose in order for the small pulley (not in picture) to drive the big pulley efficiently. The tightness of the belt creates a tension force inside the belt which pulls down on the big pulley and the shaft that it’s connected to. When the belt is pulling the axle downwards, it creates a radial force in the bearings.

for certain thrust bearings that can only accommodate pure axial loads, such as thrust ball bearings and cylindrical and needle roller thrust bearings, provided that the load acts centrically.

Bearing arrangementfacetoface

difference between back-to-back and face-to-facebearing arrangement

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.

The use of a tandem arrangement provides increased axial and radial load carrying capacity compared to a single bearing. In a tandem arrangement, the load lines are parallel so that radial and axial loads are shared. The bearing set can only accommodate axial loads acting in one direction. If axial loads act in both directions, or if combined loads are present, additional bearing(s) adjusted against the tandem arrangement must be added.

when the load is constant in magnitude and direction and acts radially on a radial bearing or axially and centrically on a thrust bearing.

If you know the expected service life of your machine, for example 10 years, and want to avoid replacing the bearings during the machine's lifetime, you can select bearings that can be operational for 10 years = 8760 hours.

Image source: https://www.machinedesign.com/learning-resources/whats-the-difference-between/article/21831901/whats-the-difference-between-bearings

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.

angular contactbearingback-to-backarrangement

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

3. Radial Impeller force As the blades of the impeller spins, they create a centrifugal force pulling on the axle, much in the same way a ball can be felt pulling on your hand with a centrifugal force when you attach it to a piece of string and spin it in a circle. When the axle is pulled in this manner, it pushes against the bearing so that a radial load is created.

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.

More than one bearing can be used at each end of an axle. If so, their arrangement should be appropriate for the load condition. There are three basic bearing arrangements:

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.

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.

Tandembearing arrangement

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.

if a bearing is loaded with simultaneously acting radial load Fr and axial load Fa that are constant in magnitude and direction

To calculate a bearing's theoretical service life, we use the formula for calculating the so called L10 life. The same formula is used for both radial and linear bearings.

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

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.

Bearing arrangement back to backchart

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.

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.

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.

Universally matchable single direction bearings can be arranged in various ways depending on the stiffness and load requirements of the application. The possible arrangements are shown in the image, including the applicable designation suffixes for matched sets. If misalignment cannot be avoided between the bearing positions, face-to-face bearing arrangements are recommended. They are less sensitive to misalignment than back-to-back bearing arrangements. Combinations of tandem arrangements with back-to-back or face-to-face arrangements are usually selected to maximize the stiffness or load carrying capacity of a bearing set in a particular direction. This is the case, for example, when extended, preloaded, vertical or overhung screw drives must be supported.

Determine the direction of the forces that the bearing is exposed to. (The magnitude of the forces will be calculated in step 4.2)

Bearing arrangement back to backpdf

Use the table below to select a bearing type that is appropriate for the load condition along with other attributes of your application.

Four forces (blue arrows) are acting on the bearings: 1. assembly weight (radial load) 2. belt tension (radial load) 3. impeller force (radial load) 4. impeller force (axial load)

The instructions on this page are intended to guide the designer through the process of selecting bearings that are appropriate in type and size for its intended purpose and load condition.

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.