Mercedes-Benz A-Class - Wheel bearing - but which side?

Honest John Back Room » Technical matters
What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks
View Threaded
Sun 1 Jul 2012 09:09
Mercedes-Benz A-Class - Wheel bearing - but which side? - the_bandit

Hi,

Car has a noisy rear wheel bearing which goes quiet when travelling on left hand bend but noisy when either in straight line or going around right hand bend.

Which bearing should be replaced?

Using the internet so far has given me answers for both nearside or offside so not very helpful !

Thanks.

Reply | Report as offensive | Link
Sun 1 Jul 2012 09:34
Mercedes-Benz A-Class - Wheel bearing - but which side? - Peter.N.
In my experience its the one that goes quite when you take the load off it i.e. when you are cornering to the left the weight is taken off the left hand bearing. Although as I say this has always proved true in my case I have heard of others where the opposite is true. The noise is usually due to the case hardening on the outer ring failing causing pits which the ball bearings are pressed into. I would go for the left one first.
Reply | Report as offensive | Link
Sun 1 Jul 2012 09:42
Mercedes-Benz A-Class - Wheel bearing - but which side? - gordonbennet

I agree, but using this method we ended up changing both front wheel bearings on my old mate's Pug 305, it was the inner bearing of the opposite side which had failed.

Jacking up and spinning the wheel freely sometimes will tell you where the problem is, but equally may not.

Reply | Report as offensive | Link
Sun 1 Jul 2012 10:04
Mercedes-Benz A-Class - Wheel bearing - but which side? - christo
It may also be worth checking the tread depth of the tyres, as when they wear down they can start to make a noise similar to worn wheel bearings especially on concrete roads. If the tyres are down to the wear indicators, then excessive tyre noise can be a sympton.
If it is a wheel bearing making the noise, it's better to replace the bearings on both wheels at one time (imho),
Regards Christo
Reply | Report as offensive | Link
Sun 1 Jul 2012 10:13
Mercedes-Benz A-Class - Wheel bearing - but which side? - gordonbennet

Fair point Christo, often worth the twenty minutes it takes to swap front and rear wheels round, see if the noise changes or moves.

Reply | Report as offensive | Link
Sun 1 Jul 2012 10:17
Mercedes-Benz A-Class - Wheel bearing - but which side? - the_bandit

Thanks for replies so far.

Should have mentioned that I'd already swapped out the tyres to eliminate one possible source of noise which didn't make any difference so focussing on wheel bearing now.

Reply | Report as offensive | Link
Sun 1 Jul 2012 12:19
Mercedes-Benz A-Class - Wheel bearing - but which side? - piggy

When I last had a dodgy rear bearing I had the same problem as as the OP. It was well nigh impossible to find out which side was worn/damaged. Having tried all the suggestions already mentioned,I took the car for a run of several miles and then felt the brake disc on each back wheel. Bingo! There was a significant temperatue differential between the two. The hottest side was the faulty one. Try to be careful when doing this though;discs/drums can get very hot!

Reply | Report as offensive | Link