Quattro noise?!

[GrahamS4]

Hi,

Since my remap, the power in the higher gears has quickly become normal to me.

However, where I am now finding it constantly evident is in 1st and 2nd gears.

I have found the car doesn't necesserilly stick to the road on the original line if you boot it too early coming out of a bend in 2nd! I have upset the car a few times where there seems to have been a flick of power to the rear, with momentary characteristics of a RWD car!

However if I give it too much in fist with any amount of lock (fronts obviously going to try and spin), I now hear what can only be described as a mechanical noise - seems to be from about middle, no further forward than drivers seat that can be heard dissapear towards the rear of the car as the power seems to transfer.

I emphasise this an extreme situation, never noticed with stock power and is something I will be aware of and not use full throttle in that situation from now on.

Is this the norm though?

Graham

[GrahamS4]

Trying to think how to describe the momentary noise, I would say a soft rachet like noise.

[Mik]

You got enough oil in your diffs?

Mik

[GrahamS4]

Wouldn't know. Serviced by Fontain about a month ago.

[oliew]

Graham, ive never heard that noise on mine, but i dont use 1st much with full throttle as i have to change before 4k because my gearbox crunches like anything 1st to second!!! in 2nd gear yes on bends you can easily get a 4wheel drift going, and letting off the power would do some other flicking of the car i think its very controlable compared to my merc cossie which was rwd hehe
not sure, is the s4 a permanent split power transfer?

[ZeroK66]

S4 can adjust 66/33 split eitherway IIRC. If it senses the rear loosing it will move torque to the front wheels.

The sound you are hearing seems to be coming from the "quattro" diff which transfers torque between front & rear wheels. Take it in to get the gearbx oil changed - something synthetic - soemthing I need to do actually. MRC should be able to help!

[GrahamS4]

Is the diff oil or associated ever changed on Audi scheduling (Annual not longlife) and if so at what intervals?

[SimonS4MTM]

No

[UKS4APR1]

Sounds like the noise the centre diff makes when you manoeuvre on full-lock and force it to slip. ?
I have had mine sideways, if you hit the boost at the right time the rear will step out like RWD, especially in the wet on a bumpy road!

[dummi]

Sounds like the noise the centre diff makes when you manoeuvre on full-lock and force it to slip. ?

front and rear are open diffs they don't lock up

[ZeroK66]

What oil are people using in their diffs/gearbox?

[snowy-d]

I've got my car going for a MRC heathcheck in July, Doug suggested that the diff oil should be changed every 80K, so I'm getting it changed then as well.

Cheers,
Mark

[shineydave]

mine was changed by Audi at service, 117,000 miles. dunno if it's been changed previously but they said it was part of the service schedule, must admit i haven't checked.

[UKS4APR1]

Sounds like the noise the centre diff makes when you manoeuvre on full-lock and force it to slip. ?

front and rear are open diffs they don't lock up

Yes, that's why I said "Centre" diff !

Centre diff is Torsen Diff.
When turning tightly there is a difference in speed between the front and rear (fronts steer and travel a different arc to rear) causing the Torsen to react similar to when one end of car starts to lose traction under power.

[dummi]

i was a little confused where you say "it" , now that i've read it again its clear you meant centre

Sounds like the noise the centre diff makes when you manoeuvre on full-lock and force it to slip. ?
I have had mine sideways, if you hit the boost at the right time the rear will step out like RWD, especially in the wet on a bumpy road!

yes torsen makes noise when its turning syncromeshes

it wont respond anything like a rear wheel drive car unless you have a rear lsd, if there no traction as suggested the torsen,, essentially an open diff with the ability to multiply torque ,, there'll be no torque to the front or rear and no drive until there is grip again. there will be synchromesh whir just as the centre diff locks up or if the front or rear loses some traction..