A6 gearbox whine

[davewelch]

My brother recently picked up an 02 Audi A6 2.5 TDi cheaply at auction. It has an Audi FSH and has done 105K. Car runs beautifully but has a slight whine from the manual gearbox at higher revs. One suggestion from a mechanic friend is that it is possibly a bearing problem in the gearbox diff? Any thoughts or opinions?
Thanks
Dave

[Niall76]

Is it 2 wheel drive or 4 wheel drive?

[davewelch]

It's a 2 wheel drive 6 speed

[Desdesigner]

I get this whine at low revs but i think its normal as ive covered 89K. May invest in a gearbox fluid change.

-Desdesigner

[spadders]

Hi guys

Get your gearboxes checked soon, DON'T leave it, I've just bought a Passat tdi sport 6 speed with the same fault.

It was the Pinion bearing on mine which is apparently VERY common on the 6 speed box. I had the pinion bearing and the other bearing on the same shaft replaced.

If left it could scrap the crown wheel & pinion which could be very expensive.

The diff can be removed & checked in-situ on this box, so it may be a cheap way to eliminate it, but if you leave it, a refurb of just the bearings costs around £700, then if the gears or crownwheel and pinion are knackered, it could cost you a fortune, if that's happened, you may as well source a new box.

The guy who repaired mine said I'd caught it in the nick of time, and there was only a slight noise in 3rd, 4th, 5th & 6th.

I hope this is of some use to you, I did a lot of research on this subject and just hope this info may save you some money

Cheers

Ade

[eeyore]

I know noises are really difficult to describe but I have a "whirring" noise on my car, which seems to be related to road speed. It's a 6 speed manual 1.9 TDI with 76K and I'm worried I may have this bearing problem. It's not a whine as such, more like someone blowing a kazoo :confused:

The noise is only just noticeable when driving over about 40mph and is most noticeable when slowing down, say to a junction with the radio off. Dipping the clutch doesn't affect it and neither does road surface as far as I can tell.

Can anyone who's had this problem confirm if what I have sounds (pardon the pun) like the same problem??

[davewelch]

Hi,

That does sound similar to the sound that I was getting on my 6 speed A6 and unfortunately this was due to the fault described above. Definitely worth getting it checked I would say,

Dave

[eeyore]

OK, well I jacked up the car this morning and spun the front wheels out of gear. There's nothing major but there is a very slight click/notchiness in some places as you turn the wheel around. No noise from the wheel area itself.

Is this normal or should I be getting worried :(

How much should the pinion bearing work cost if it is required??

[Peter D]

Are you sure this is not a wheel bearing giving notice, does the noise change with direction of steering as the wheel loads up. Regards Peter

[eeyore]

No change of noise with wheel direction.

Last weekend I fitted a set of 18" wheels, which I've just swapped back temporarily to the original 17s. If I listen really carefully I can just make out a similar noise but it is much quieter. With the 18s on it's quite prominent.

I'm thinking tyre noise then (as much as it doesn't sound like it)? Surely if this were gearbox/diff the wheels wouldn't affect it?

[Peter D]

If the offset is correct then it sounds like you have tyre noise. What are fitted to the 18" rims, make and size profile and J number. Regards Peter

[eeyore]

The wheels are RS4 replicas 18" x 8JJ ET35 fitted with Diamondback 225 40 18s ("A" tread directional tyres). Offset seems fine, nothing catching, all treads running the "right" way. They do sit about 10mm out of where the original 17s were so fill the arches nicely.

Do you think any of that will make a difference to the source of the noise?

[Peter D]

Diamondback are not known for noisey tyres but being new and on 40 profiles will raise the noise. Regards Peter

[eeyore]

Thanks Peter. Plan is to run the car on the old wheels/tyres for a couple of days to be sure then put the 18s back on if everything seems OK

As long as it is only tyre noise I can live with it!

[paul b]

On the subject of the gearboxes, those noises sound like they should be checked out.

Had a very similar 'whirring' noise on my Renault van (also a 6 speed) and after a long 3 hour motorway trip without touching the brakes or changing gears for a good hour or two I came off the motorway and the sound was far, far more prominent. As mentioned it was the bearings that needed replacing, so the gearbox was fully reconditioned.

I know its not an Audi but the principles are the same.

Its the works van so I didn't offer my services. ;)

Paul

[eeyore]

Well I ran the car into work today (25 mile mainly motorway commute) on the old wheels/tyres. If I really listen for the noise I can still pick it out but really very much in the background and much quieter. Problem is of course I'm now driving with no radio and even the fan off to try and pick out the sound :(

Anyway it is definitely much improved on these wheels to the point where I probably wouldn't have noticed it before.

So, I'm thinking:

(a) tyre noise (and what I can hear now is quieter, older tyres.)
(b) wheel bearing (being loaded differently with the larger wheels hence louder noise)
(c) "normal" transmission noise
(d) something else!

Seems unlikely to be gearbox or diff as (I assume) neither would be affected by changing the wheels over :confused:

Any expert opinions welcome!

PS: reading some other posts on this I've held my hand on the gearstick which makes no difference to the noise.

[Niall76]

I doubt it's the wheel bearing. It would rumble away just the same.