Trying to find the source of a hum

[pauldunlop22]

I have a 2002 V70XC with 105,000 mi. Recently I noticed a low hum coming from the car. becomes noticeable soon after starting off.
I thought that it was very similar to when my right wheel bearing went a year ago. That was front rt side. We checked both front wheel bearings . Right still excellent and Left needed replacing, which my mechanic did. But that didn't fix it!! I am thinking maybe rear bearings, but does this ring any bells with anyone? I tried shifting into neutral while in motion, no effect on the vibration.. I would appreciate any suggestions. Thanks

[AKAMick]

My 04 had a hum and as you, both front hubs are fairly new, it was coming from the rear but I could not determine which side, so I bought both and sure enough the right side was rough, I still replaced both sides, as after doing the bad side and realizing that it is pretty straight forward and quite easy, and having the tools already out, I did them both. Maybe if you have a helper that can listen carefully to both sides while in motion you can determine which side is bad. If it is a rear hub at all.

[pauldunlop22]

Thanks for that suggestion. My mechanic was thinking it might be the right rear also. I have had the car for eleven years so maybe we will replace both original rear hubs. Hopefully, this will solve the problem. I will keep you posted. I am open to any other suggestions too. I love my car and it has been a joy to drive. I have had few problems.

[Iroll_]

Which brand of wheel bearings have you folks been using?

[pauldunlop22]

My mechanic uses SAG for durability.
He says for some reason he replaces more right rear units to left rear units at rate of 7 to 3
So.i plan to replace both rear units Tuesday
I hope that takes care of the hum !

[Iroll_]

My mechanic uses SAG for durability.
He says for some reason he replaces more right rear units to left rear units at rate of 7 to 3
So.i plan to replace both rear units Tuesday
I hope that takes care of the hum !

Much appreciated.
I've been trying to track a humming noise too.
I'll take a look on the right rear.

[pauldunlop22]

Hi again, so far have not located source of hum. all 4 wheel bearings feel ok (2 front recently replaced)
my mechanic placed sensors on 4 locations bottom of car. nothing definitive. he wants me to wait a little longer drive car for 2-3 weeks hopefully sound will be more pronounced ..
any suggestions?

[Antherzoll]

Get it up on a lift or four jack stands safely and run it. If you can hear the noise then locate it accordingly, if not then it may be load dependant or tires, bearings, suspension, or collapsed mounts/bushings.

[Iroll_]

Carrier bearing(s) or noisy differential(s)?

[pauldunlop22]

Thanks for your suggestions. I am bringing it in today for another assessment. I have been driving it for a while and now the noise is very loud hopefully will find the source will consider your suggestions and will let you know what we find.
Bye for now...

[pauldunlop22]

Update: took car in today. Mechanic said that he was wondering if the problem was bevel gear! But he sensed that the right front bearings were a little un even so suggested check and replace them. He took car out for test drive. Problem solved!!
What a relief. Thank you for your helpful suggestions and support. Some of these problems difficult to check without a load.
Though my car still has some issues it is fun to drive and familiar and comfortable as a pair of old jeans. At 105,000 mi I hope that I have lots of time left to enjoy this ride.

[Astro14]

at 105,000 miles...I think you've got a LONG time left to enjoy this car...you've got half the miles that my wife's XC has...and it runs perfectly!