My trusty A4 (2.8 quattro) has, at 136,000 miles, suddenly developed a Noisy Diff - well, I think it's the diff, i'm getting a loud, deep "humming" kind of a noise from the back of the car - it's there all the time, under acceleration, braking, coasting - I've even tried turning the engine off whilst coasting, and I can still hear it just as loud as ever....</P>


So... is this a known problem on A4's with a few miles on them? Am I likely to be able to live with this, or could it be the precursor to something serious?</P>


All ideas/advice gratefully received....</P><edited><editID>JohnL</editID><editDate>38111.402337963</editDate></edited>

 

Quite possible you have a wheel bearing that has died. It's a common thing on our cars. Get it checked - about $250 to have it fixed at the dealer if i recall correctly.

 

S'pose I can validate if it's a wheel bearing by jacking the rear of the car, putting it into neutral, and spinning the wheels.</P>


It it IS a bearing, my local garage will do it for less than £100. If it turns out to be the diff, I need to know whether it's something I can live with (my old Rover V8 P6 had a noisy diff for 50,000 miles with no problem) or whether it needs fixing.</P>

 

yeah sounds like a wheel bearing. not to bad to replace<IMG src=smileys/smiley11.gif border="0">

 

whens the last time you had the fluid in the diff changed?