wheel bearing

Is there an acid test to check wheel bearings? I'm getting a lot of road hum comming from what seems to be one of the front wheels. Is there a way to tell if it's the bearing? Also, if it is a bearing, do I have to do anything special with the locking hubs?

Acid test?

Your're blazer doesn't have locking hubs, the hubs are always locked into the axle shafts. The axle shaft itself engages and disengages.

An easy way to tell if a hub bearing is causing a noise is to listen on turns. Make a few "S" turns. The noise will change with left and right hand turns.

More than likely it's one of your wheel bearings with that hum... The acid test is to jack up the front and move the weel, anything more than a mm of movement in the hub while rocking the wheel (look at the back of the hub while doing this) you will need to replace.

Just replaced a bad drivers side wheel bearing on Transport. It looks simular to my Blazer. The sound was a low growling that increases in ptich as you go faster. it for sure came out of the wheel in question.
More than likely, you will need the whole assembly if you have 4 wheel. the assembly will be the spinner and bearing assembly all in one and it will set you back about $90.
After replacement, the growling is gone and the car is happy once again!

An easy way to tell if a hub bearing is causing a noise is to listen on turns. Make a few "S" turns. The noise will change with left and right hand turns.


The hum disappears on S turns and does get louder as speed increases. I have the repair manual and it looks pretty straight forward. Anything special or tricky I should watch for? The funny thing is I'm going to be doing this on my kids Grand Am later this week.

Settle something for my GF - when refering to left and right in a vehicle is it from sitting in the vehicle or standing facing the vehicle? I know the answer but my GF refuses to believe it maybe your answer while get through to her!

Acid test?


Yes - Acid Test. Meaning an end all positive proof test.

The hum disappears on S turns and does get louder as speed increases. I have the repair manual and it looks pretty straight forward. Anything special or tricky I should watch for? The funny thing is I'm going to be doing this on my kids Grand Am later this week.

Settle something for my GF - when refering to left and right in a vehicle is it from sitting in the vehicle or standing facing the vehicle? I know the answer but my GF refuses to believe it maybe your answer while get through to her!
Oh the girlfriend excuse...........if you wanna know just ask :)........ Just kidding.

Left and right is determined by sitting in the vehicle. Driver's side is left and passenger's side is right.

The tell-tale sign of a fading wheel bearing is a growl accompanied by a vibration. The sound and vibration will increase with vehicle speed. While turning in one direction the symptoms will get worse and while turning the other they will seem to fade away (unless both sides are bad). Usually the right front is the first to go.

You can search this forum.... a lot of walkthroughs have been posted.

how are your tie rods?

how are your tie rods?


I dunno -What do I look for?


Nice Blazee - Yes it is a real argument. My GF complains of something on the right front - like with the tire- and I go out looking and guess what - I don't usually find anything!

Thanks guys!

pull the front end off the ground, if your wheel is locked and you can move the tire left and right, tie rod ends are bad

up and down is to check the bearings.

left to right play is the steering assembly.

Ok, I went for a ride... when I turn right the sound stays and when I turn left the sound disapears. I should have some daylight left afterwork today to lift it and check for play.

yip, if you turn left and unload the driver's side wheel and the noise goes away, you have found a bad bearing.

I got home and lifted the truck. The right side clunked when I rocked it top to bottom. Just S & G's I lifted the left and it was rock solid. The next question is what's better - GM or aftermarket??? I can get the GM part for $185 shipped and the aftermarket for around $100.

Any thoughts?

i would do aftermarket, but the only thing i buy from a dealer is a pcv valve

up and down is to check the bearings.

left to right play is the steering assembly.


What if there is play both up/down and left/right, but no noise? I can wiggle the front right tire on my 2001 2WD atleast a half inch by lightly pulling on any one side and pushing on the other.

I have 110,000 mi on the blazer. I had the hub & bearings replaced on that wheel about 20,000 mi ago. It was quite noisy before it was replaced. I don't currently hear any noise though.

Is that bearing going bad again? Since theres no noise, is this amount of play ok for now?

I just don't want the wheel to fall off while I'm driving. All of the other wheels are solid, it's just this one that concerns me.

Thanks guys. Great forum, it's been very helpful for me. I've saved quite a bit of time and $$$ by searching through it.

Left and right means that you have play in your steering assembly.

Bearing play is up and down.

What if there is play both up/down and left/right, but no noise? I can wiggle the front right tire on my 2001 2WD atleast a half inch by lightly pulling on any one side and pushing on the other.

I have 110,000 mi on the blazer. I had the hub & bearings replaced on that wheel about 20,000 mi ago. It was quite noisy before it was replaced. I don't currently hear any noise though.

Is that bearing going bad again? Since theres no noise, is this amount of play ok for now?

I just don't want the wheel to fall off while I'm driving. All of the other wheels are solid, it's just this one that concerns me.

Thanks guys. Great forum, it's been very helpful for me. I've saved quite a bit of time and $$$ by searching through it.

You don't grease your front end at every oil change.....do you?

For the left and right play, check your inner and outer tie rod ends, idler arm and pitman arm. Have someone move the wheel, while you look for the problem. Everything should move together, the part that doesn't is bad.

For the top to bottom play, check your upper and lower ball joints. The tire should not move while pushing and pulling from top to bottom. Any movement indicates a problem. While someone is moving it back and forth look from behind to see if the slop is in the ball joints.

You don't grease your front end at every oil change.....do you?


The shop I used to go to wasn't. The front end would creak loudly during sharp turns like in parking lots. It looks like they would just hit the easy zerks, and skipped the hard to reach ones like upper ball joint.

I do my own oil/lube now, and the creaking is gone. I would imagine there has been a lot of premature wear from the lack of grease, so you're probably right.

I will do as suggested when I get a chance later this week. Thanks.

Yip, all 11 grease fitting need to be greased every 3000 miles.

Is there a difference in movement? I rocked my wheel left and right and there was movement but I'm not sure it was "play". The other wheel moved just as much. Should there be any movment at all?

As long as both wheels moved together, your steering linkage is okay.
Try moving your steering wheel back and forth and see if the wheels move in unison with it, delay between the the movement of the steering wheel and the movement of the the tires could be a sign of a worn rag joint.