bad bearing detection tool/technique

[medinacaver]

What tool or technique would work best to detect which bearing is failing (alternator, AC, PS, Tension/idler pulley, water pump) ??

My ability to isolate noise is poor, and I would rather use a tried/true method. These parts are too close together.

Relevant info: 2007 Toyota minivan w/serpentine belt

I have a cheap automotive stethoscope, but gaining physical access is difficult.

Could one successfully use a 'Steelman Chassisear' for these type of bearings. Not that I have this tool, but could possible justify a purchase.

Thanks, MC

 

[Carguy99]

take the belt off and spin them by hand.feel for looseness and play. heat is another good indicator... the bad one will be hotter.

 

[elderstarr]

Use an extended rod on the stethoscope.

Would be worried about using the chassis ear, due to wires hanging near rotating parts.

If access is too difficult to easily remove the belt, you might have to take off a tire and the inner plastic fender.

 

[Subyroo651]

Funny this topic would pop up, I was just hunting down a howling noise on a 2010 Hyundai Genesis. Think I narrowed it down to the Idler pulley, seems to be a common issue with them, only 30K miles too!

I used CarGuy99's method, its pretty much the best, otherwise you can be deceived by all the happenings when the Engine is running.

 

[y20dth]

An old train mechanic taught me to use a big screwdriver.
Put the tip on the bearing housing, and the handle to you ear.

 

[zkling]

Quick? A screwdriver or similar piece of steel that is extremely hard. Just use caution around moving components.

All out professional/crazy? A stethoscope.

Ultimate? Accelerometer and appropriate data acc device.

 

[richfinn]

Decent quality Stethoscope works for me (I do take the belt off sometimes and spin stuff by hand).

I will sometimes use an IR temp gun/screwdriver or for wheel bearings I drive the car hard through left and right turns to load up the bearing and make a decision.

Tried the electronic stethoscope at the dealership and didn't care for it much, saw a lad replace a whole host of parts and then I found a noisy alternator using a long screwdriver.

I think the chassis ear would be best used for chassis NVH rather than engines as you say to much going on in an engine bay to isolate the source.

 

[jeremy v]

One tool that I made that I really love is a stethoscope and earmuff combination out of harbor freight stuff. I purchased the standard couple dollar orange harbor freight earmuffs and drilled a hole in each one so that the stethoscope could fit into each of the ear cups and still rest on my ears while wearing the muffs. That way I can get a boost in sound from the stethoscope and also deaden the sound of the running engine etc. to make it more effective. I got the stethoscope from harbor freight also, and I think the whole setup cost me less than $10 plus about 10 minutes of my time.

I second the IR temp gun recommendation especially for things like wheel bearings, differential bearings, and other harder to physically access bearings. Bearings will start to run hot when they get low on lube often without making any extra noise, so an IR thermometer is a better preventative maintenance tool than a stethoscope in my opinion. For something like wheel bearings, I just take a test temp between all 4 wheels after driving a while and if one is noticeably higher in temp then it needs to be looked at, lubed, etc. Also sometimes it can be awkward using just a stethoscope on an alternator or electric motor that uses brushes. The scraping sound of the brushes on the commutator can easily transfer to at least the rear shaft bearing (that is usually right next to the brushes) and make a good bearing sound like it is dry or about to go out, but the temp gun can help you to verify if there really is a problem or not.

 

[unslow1]

I may have to steal that ear muff modification idea.

 

[Jagmandave]

Yeah, that's a pretty good solution there......my HF stethoscope ear buds are prone to turning and coming out of my ears, this might help stabilize them.

 

[jamesc]

I learned a pretty good trick for wheel bearings, with the wheel spinning grab ahold of the spring and if you have a vibiration that will be the bad bearing. You can compare the vibiration side to side and feel the difference.

For engine belt and bearing noises I use a mechanics stethoscope or a long screw driver. taking the belt off is a good way to go but some times you miss things that are borderline that you would hear with a stethoscope.

 

[jmm]

If you have room and a bit of thin rope or thick shoe string and you can't pinpoint it any other way or don't wanna drop cash on a nice stethoscope here's a trick: Engine off, belt removed. Knot the rope, and hook it around the pulleys, one at a time, loop the chuck of a drill (the quietest one you have) in the other end of the rope. Get the drill moving. Listen for anything other than a smooth glide.

 

[jethro29]

I do sometimes remove the belt and feel each pulley for roughness or temperature.i do have a chassis ear which is a great tool,just not for this.what I do is use a stephoscope,just like the one pictured only you remove the metal rod and the chamber and install in it's place a piece of brake line that fits tight in the hose,this works GREAT I also use it to listen for exhaust leaks and for loose cats.

 

[kams1973]

a wooden dowel such as a broom stick cut down would work nicely

 

[scarney1988]

Please PM with your email address. There is a service bulletin which applies to your engine. Essentially, the 2GR-FE has two idler pulleys which begin to make noise (or just one while the other waits a bit longer to fail). The TSB provides part numbers etc...

If you need further help, just ask.

I like to use a long 3/8 extension or long flat screwdriver and press it on the mounting bolt or on the accessory case to listen for humming of grinding. I've used pry bars, long ratchets, stethoscopes, files all with decent results.

 

[OccupantRJ]

Does no one but me ever use a piece of rubber hose to listen through, to isolate noises?

 

[Outlawmws]

I have a converted cheapo medical stethoscope, a piece of 1/4" (or less) copper tubing as the probe jammed into the rubber hoses, and a wood screw driven into the open end of the copper tubing as a "microphone"

Without the wood screw, its absolutely useless, with the wood screw, the damn thing hears EVERYTHING and you can move it an inch either way and tell the difference...

 

[wafrederick]

I use a long skinny screwdriver,handle side to my ear and the tip near the noisey part.

 

[PCO6]

Does no one but me ever use a piece of rubber hose to listen through, to isolate noises?

That's an old trick and it works well. I also use to use a hose for tuning SU carbs.

 

[Rico.]

I also use to use a hose for tuning SU carbs.

Ahh... You just brought back memories for me of seeing my dear departed Dad looking
like he was using an SU carb as a hearing aid...

 

[KinzeMech]

If it's locked up, balls have fallen out, or it's come apart, it's bad.

All else is not bad *yet*.


To be serious though, noise, free play, and the feel when turning by hand are my criteria. That, and smoking. If it's smoking, it's bad.

 

[PCO6]

Ahh... You just brought back memories for me of seeing my dear departed Dad looking
like he was using an SU carb as a hearing aid...

... hhhsssss

 

[torqueman2002]

An old train mechanic taught me to use a big screwdriver.
Put the tip on the bearing housing, and the handle to you ear.

I know this is an old thread, but I learned a new twist to this tip/trick.

Eric O from South Main Auto, on YouTube demos how he amplifies the sound safely.
<iframe src="https://www.youtube.com/embed/fHtLH_m9gN4" allowfullscreen="" frameborder="0" height="315" width="560"></iframe>

 

[unslow1]

I've never seen the jug on the screwdriver before. I have a mechanic's stethoscope with a set of ear muffs drilled for the ear pieces. Post #8 shows a pic.

 

[2oolhound]

THX torqueman2002! gotta try that one.

 

[torqueman2002]

I've never seen the jug on the screwdriver before. I have a mechanic's stethoscope with a set of ear muffs drilled for the ear pieces. Post #8 shows a pic.

Hey, thanks.

I just remembered why I ordered that extra pair of ear muffs!

No kidding. I have ones with build in radio and mini-jack input, and 2 of the 3M earmuffs.

For the life of me, I couldn't remember why I bought the 2nd pair.

 

[Outlawmws]

Well that was surprisingly impressive! I like my copper tube/wood screw/stethoscope, really well ( Post 17 - much better than commercial stethoscopes I've tried) but that one is a good one to remember if I'm not at home!

 

[ex-x-fire]

Sometimes I'll use one of these to spin a pulley up fast.

 

[torqueman2002]

Sometimes I'll use one of these to spin a pulley up fast.

I'll be using that. Thanks.

 

[bdelmar2]

I've always used a screwdriver to find noises like that - carefully.

Rubber hose works good to find vacuum leaks, but I don't have as good of luck with bearing noises.

For a wheel bearing you can try moving it, but with new sealed bearing assemblies the bearing can be in really bad shape and won't give by pulling on the wheel, at least by hand.

If its front wheel drive you can raise the front of the car, turn off traction control if the vehicle has it, and have someone run it up to speed while you listen at the wheel, if its bad you can hear it then.

 

[MikeF2316]

If there's a way to place the bearing under more load, then the noise will get louder. Wheel bearings are easy to do. If you turn left, the right sides will get louder. Hard breaking will make fronts louder.

On some cars with the automatic serpentine tensioner, try manually pulling the tensioner in the tighten direction, this may make the noise louder and easier to spot.

 

[unslow1]

Sometimes I'll use one of these to spin a pulley up fast.

Can you hear it over the air tool?

I never thought of increasing the tension to make it louder.

 

[Roberts210]

I use a large, long wrench. Hold one end to my ear and the other to the suspected culprit. Works for me.

 

[shermanklove]

I've always used a long screwdriver to my ear. Just found out about this method and I can't wait to try it.

 

[ALLFAST]

These are all great ideas. For larger pillow block bearings that have safe access we use a wire brush. The wooden handle does a great job....dowels as well.

 

[arbormatt]

As my older coworker taught me. Stick-o-scope