a8 drive train

[billy5]

hiya all,
as the car gets warmer, say a mile or so,
round 30 to 40 mph there is a sound like a worn bearing.
wen you turn the wheels into a bend at the same speed,
it seems to increase,
upwards in speed its quite as a mouse,
am i right to say if it was a fault in the drive,it
would get worse at speed.
its on 19 alloys,
tyres are not very old and all equal in tyre depth.
any ideas,,
ta billy

[Dilligaf10]

Don't be too hasty in blaming the drive train. Could be the "sawtooth" effect on half worn tyres, I have the same on mine.

What tyres are you running?

[billy5]

hiya dilligaf 10,
i,v had a look at the tyres
the front ones are; falken 255 40 zr 19 100y [nearside]
federal supersteel 595 255 40 zr 19 96w [offside]
the rears are both khumo.
the falken was put on in april 09, i think,
only had the car for a week,,
the noise seems to be increasing at thirty to forty
going into tightish dends, you feel it slightly through
the steering whl, no shake at all but you feel somethig on the throttle.
as i said, at 60 on it goes,
got it privatly,
ta billy

[ukdennis]

You need to replace the tyres pronto.

Audi (quattro) handbook says the type of tyre must be identical on a single axle, and highly desirable on all four wheels.

[Dilligaf10]

UK Dennis is right, they are very tyre sensitive. Certainly would not run different tyres front to back let alone different ones on the same axle.

[billy5]

hiya,
ta for the good advice,
do you think it would work if i put two new khumo,s
on the front axle,
seems this is the problem.

does anyone have keyless go,,
is advanced key the same thing?
ta very much,

[Tame Technician]

40MPH is bang on the money for tyre noise.

[billy5]

hiya all,
got some brigstones for the front to start with,
will see how it goes, not on yet, be tuesday
have i made the right decision..
ta billy

[ukdennis]

You really want to be having the same type of tyre on all four wheels, and even then it's not good having two brand new ones on one axle and two very worn ones on the other axle .... too much difference in rolling radius for the quattro system, as has been noted in previous threads.

Edited by ukdennis on Friday 7th August 07:56

[billy5]

the khumos on the rear have about 6mm left,
i see the point ukdennis makes ,
i suppose i could have got four cheap tyres[new]
but i went for good ones, £416 for two,
i will get another two to match the fronts
wen i can afford,
its not worth it to get used ones as they could have been
taken off for the same symthoms as i have,
dont do many miles, 4000 per year so new tyres will last me
till
i get my bus pass,,

can i mess about with the tyre pressures slightly [front to back]
till i get new rears, will it work,
ta for all your help,
billy

[billy5]

yia all.
put the two brigstone p,s on the front today,
there is still a slight bit still there
but really nothing like before,
got to be down to the rears,
will do the backs wen i get some spare £££
kumos have 6mm on each.
think i,ve sorted the advanced keyless go,
getting there,, wow

ta to you all for the advice,, billy