Another whining noise question

[jblackCLK]

Hi all.

My cars has developed a whining noise over the last three months, its really hard to pinpoint where its coming from as if I turn my head one way its coming from the front drivers side but if I turn my head another it could be coming from the rear??. The noise is most apparent around 30mph and disappears on the motorway (although it could be being drowned out by the engine noise). If I drive at 30 and put the car in neutral and coast it is still there so its not the engine or gearbox, and it increases when I break to a stop (becoming a rumbling sound which I can slightly feel through the floor). I've had the gearbox oil changed about 6 months ago and there is no banging or knocking.

At first I thought it was a wheel bearing but I've had the fronts replaced and the rears checked. I then thought it could be brakes so I've fitted new pads and disks to the front but still the same noise.

I'm now thinking its either diff or something to do with the drive shaft. I'm going to change the diff oil tomorrow to see if this changes anything but in the mean time does anyone have any ideas or advice on what the check next??

Many Thanks

 

[Dieselman]

If the tyres are wearing down they can cause a droning noise, otherwise it's probably the engine/gearbox mountings or the differential mountings or possibly bearings.
Check the drive shafts for lateral movement by pushing up and down.

Changing the diff oil might make the diff generally quieter, though probably won't necessarily remove a specific noise.

 

[benzzi]

Hiya,had a whinning noise on my merc turned out to be the tyres.you could check by swopping front ones with back .