Speed-dependent Howling / Humming from front end - not sure if it's bearing or tires

944tothefloor · 06-28-2015, 09:11 AM

Can anyone recognize this? Please?

It's a loud noise that gets louder as speed increases. It's a significant howling / droning / humming. It starts getting pretty loud a 40 mph.

It's coming from the front end...I cant really tell if its one side or both, but it's definitely coming from the wheel assembly area(s).

Could this be tires noise due to bad rotation? The tires are newish with good pressure.

Could this be a wheel bearing? The noise doesn't really change when the vehicle turns.

I would like to solve this problem of course, so any help is appreciated! Thanks!

Dr DIY · Dr DIY's Garage

Step #1 is to get the wheels up in the air and spin them by hand. If it is a bearing you should be able to tell.

thomasryan · 06-28-2015, 04:28 PM

I have had lips on the rotor 'sing'

Bradical · 06-28-2015, 05:32 PM

The front bearings are stupid easy to remove and regrease, in comparison to the king arthur sword-in-the-stone extraction nightmare that is the rear bearings.

sausagehacker · sausagehacker's Garage

Jack up the front and wiggle the wheels.

https://www.youtube.com/watch?v=Nq1zGxnF8Qk

968 GUY · 968 GUY's Garage

I had Sumitomo HTZ 2's on one of the 968's that started a horrible howling after they got several thousand miles.

I did think it was the bearings and actually changed the rear ones. Found out it was the tires after swapping the ones from the 951 to the 968

mytrplseven · mytrplseven's Garage

If your tires aren't staggered in size (front to rear), I'd suggest moving the rears to the front and see if that changes what you hear. Then you'll know for sure if it's tires.

944tothefloor · 07-01-2015, 01:39 PM

I'm going to lift the beast up asap and try to wiggle the L front wheel. I'll check the lips of the rotors. Then, depending, I'll switch up the wheels. The bearing might just need regreased, it sounds like.

Thanks!!

944tothefloor · 07-01-2015, 06:10 PM

Ok, L front wheel definitely has unwanted play, and R front wheel has less play, but probably too much. However, the wheel did not make excess noise while I spun them.

Thanks for your guidance folks. If I get get one last question in, what are some recommended / trustworthy bearing replacement parts?

thomasryan · 07-01-2015, 06:21 PM

I like SKF and FAG would be my second choice.

Van has a video on replacing the bearings. part one

Heat is your friend

944tothefloor · 07-01-2015, 08:01 PM

So I've got 2 front inner bearings, 2 front outers, 2 seals, and a tub of moly grease. is that about it? Pelican parts has all the parts

pfarah · pfarah's Garage

I agree with Thomas, SKF is the way to go.

Jfrahm · 07-02-2015, 06:51 AM

If they make noise when spun by hand they are *really* scary. Play is enough to cause a lot of humming.

thomasryan · 07-02-2015, 08:26 AM

Adjust them first per either method...

60 grams of lube is preferred.

HEAT will save a lot of frustration and angst....I suggest bringing home flowers for a few days before you stank up the kitchen))

944tothefloor · 07-02-2015, 09:01 AM

Haha, glad you mentioned the flowers ahead of time. So I was about to place the order ... 2 front inner bearings, 2 front outer bearings, 2 seals, and moly grease. Is this all I would need?

However, it's still possible to adjust them you say? I thought since they were humming I needed to replace them. Turns out my records show they are only 35,000 miles old. Adjust or replace? thanks!

thomasryan · 07-02-2015, 09:52 AM

Right on....adjust them (I like vans method) and see if the noise changes.

If not.....place your order but get 4 seals. Pull the hubs. Clean them and inspect. If they feel good and no blue spots or chaffing, repack them and put your new ones in the glove box....but keep buying flowers.

When the rotors have reached their wear limit with a decent lip, the pads are like a wet finger on a leaded crystal wine glass...not sure one would ever hear it over the belts though.

944tothefloor · 07-02-2015, 11:54 AM

Okay, I adjusted the loud one, on the left side. Doing the job was easy as pie. I can see that replacing them is slightly more involved. I did find that the washer was too tight, and I adjusted it, so I'm hoping I see some improvement.

However, the amount of play that was not remedied worries me and I still think I'll order the parts. Is it possible that misaligned front wheels caused the 35k-mile-old bearings to go bad already? Or does a bad bearing cause a worn tire? My left/front tire is showing some inner wear, so I moved it to the rear.

thomasryan · 07-02-2015, 12:20 PM

Cool...lots of good DIY threads on the bearings. 60 grams.

As a rule, if a tire can move with a load...fix that problem. Everything on the front is a wear item except for the spindle and the control arm body)) When everything is fresh, it is nirvana.

944tothefloor · 07-02-2015, 09:06 PM

This one is turning out to be a little convoluted.

This is kind of one of those follow-up posts that is meant to help others in the future, or me in an alternate universe. After loosening the thrust washer AND moving the worn tire to the back, the noise is a LOT quieter.

So now I'm thinking that the bad front alignment has caused the tire and the bearing to wear too quickly. Although the bearings are only 35K mile old, I'll replace them and get the front end aligned. I'm pretty sure that is going to end the problem.

So long story short, I think a bad alignment caused stress on the tire and the bearing, and the worn tire caused excess noise and then caused the bearing to get worse faster, which caused even more noise.