w124 front wheel bearings.

[simon_wall69]

Driving back from Scotland on Sunday, I noticed at speeds over about 30mph a whirring wheel bearing noise coming from the front wheel.

I thought I'd leave it as the car was going for its MOT test today. It went through and passed needing only bulbs and a new brake pipe.

The mechanic said that the noise was indeed a wheel bearing noise but the MOT tester hasn't failed the car on it or given it as an advisory.

Anyway, how do I know whether the bearing needs replacement or just adjustment and if it is adjustment how easy will it be to do myself. Or, as been as though it wasn't an MOT issue can I just leave it?

Car is an E300td

 

[television]

Hi Simon once they are noisy it a replacement job and very easy to do, I can give you the info if you are doing it your self though any garage could change it in no time

 

[Number_Cruncher]

>>Or, as been as though it wasn't an MOT issue can I just leave it?

No! The MOT is rather a blunt instrument - it's quite a good, sensible check, but very limited in scope. The MOT tester can do NO dismantling whatsoever, and for a wheel bearing to fail the MOT, it has to be loose, or very rough and noisy indeed.

As an example, when my W124 front wheel bearing failed, you could not feel it or hear it by spinning the wheel by hand. I only found it when I had taken the brake disc off - I was fitting new discs and pads at the time. One of the rollers on the small outer race had failed completely!, and it was only a matter of luck that the race hadn't spn and friction welded itself to the stub axle. This serious failure could only be felt from the hub - if the disc was in place, it's inertia masked the roughness. I stopped my brake work, and sent SWMBO off to buy some front wheel bearings!

As Malcolm says, they are not a difficult job to do. The only tricky part is that to set the clearance to MB specs, you must use a dial gauge - the setting is much tighter than on other makes of car, and many garages will get these wrong!

 

[simon_wall69]

Thanks, I'll ring up and get it sorted. I don't fancy doing something like this myself when there are settings and such to have to do, I'd rather let a trusted mechanic do it.