Do I need a new rear wheel bearing?

[TheJoker]

Hi gents,

Long time no type. Can only mean my car is running alright!  Well almost. 

It's developed a buzzing sound from the right rear of the car. It's speed related in a linear manner (more speed faster buzzing). I started to investigate today and I took the right rear wheel off. Couldn't spot anything by spinning the wheel. Then I took the caliper off and put the wheel back on and spun the wheel around, and yes, there's a bit of a clunking sound.

Is my diagnosis correct?
http://www.youtube.com/watch?v=aEEredvLAV8

Wheel bearing needs replacing? Is it difficult to do? Does it need any special tools?

[jack daniels]

yes this sounds like the wheel bearing. If you can take off the caliper yourself then you can replace the wheel bearing too.
you'll find one on ebay for about 100 euro. Just verify it's german made and not chineese. standard tools only are required, the only thing you'll need in addition to what you must have used allready is a socket for the retainer nut, a torque wrench, torx keys to remove the brake disk, a small punch about 5mm dia. to lock the retainer nut, and that's about it. The torque for the bearing retainer nut is 170Nm. You may as well buy 2 at once if you can save some postage,  the other side will probably go within a year of the first.

...didn't notice the youtube link. It was a bit hard to hear but the speed related buzzing you describe is typical wheel bearing. There is not really anything else that can make noise when you rotate the wheel as you did. Just check the ABS ring is in place and not rubbing on the sensor. Its part of the bearing anyway so a new one is included with a new bearing, however you should check that the sensor part is not damaged.

[TheJoker]

Thanks very much for that insight! I'll look into buying the bearings and see what I can do. I'll also have a peek in the PDFs to see what they say about it. Might also ask the local garage what they want to change them.
Thanks again! 

[TheJoker]

Thanks for your help, jack daniels!!

It was easy peasy lemon squeezy!  
I decided to go for a Korean bearing (Orion or Origo?) as the car has now done 105,000 miles and if the new bearing lasts up to half of what the £155 bearing then I'll be happy. You were also right; you can get cheap bearings for ~£50 on eBay and quality bearings for ~£100. The £155 was from a local car parts shop. The £74 I paid for mine was from Euro Car Parts.

Car is quiet again!! Thanks once more!

Oh, and I posted pictures and how-to here: http://www.matrasport.dk/forum/index.php/topic,1865.0.html