Tranny screaming. Sounds like ...
 

... when you screw up a shift on a manual transmission and the syncros whir and whine. The noise is engine RPM related, not roadspeed related.

My mechanic flat-bedded it to his shop this morning, and at first there was no noise, but there was a nail in one tire and the cam seal on the passenger side was leaking LOL ...

Then on the second test drive, it started to scream for him as well.

His mechanic suggests broken pieces in the torque convertor are whirring around in the housing as it spins.

I told him to quote up a rebuilt unit, installed. Bleh.

edit ~~ I asked if it could be very low fluid, and he assured me they checked that before he called and it's full.

Could be the filter has dislodge and is causing the hydraulic pump to cavitate
 

If the transmission still works, I would change the fluid/filter and see if it goes away.

It's been hunting but not thumping for several months
 

I'll know more when they crack it open I suppose. Once the hunt started at 100k, I knew this moment was coming.

How loud is the 'screaming'? Mine's been 'whirring' in 1st, 2nd, and part of 3rd for about...
 

...2 weeks now. Mostly when cold, and not all the time only sometimes.

Sounds like a supercharger whir. I figured it was just 2nd but it's not. Then I figured maybe the front diff, but your post has me wondering.

When it's cold in the a.m. and the car's cold, if I try to shift in tip the shifts are quite herkyjerky.

Report back, good luck.

Same here, jerky when cold and slight whine in first.
 

I figure if it aint broke dont touch it. The only odd thing is on occasion I get a defined super charges whirrr from the front on start up. Quick shut down and start up shuts her up. Really have no idea what that one is...

The only thing that is consistent is a soft thud into fourth at slow speeds, community speeds. Only I notice passengers think it was a bump.

seems like a lot more tranny problems cropping up now that the weather is colder.
 

I'm gonna pull my wife's car in tomorrow night and start to look at that tranny issue.

Maybe if I'm lucky I get to do the whole job over again!!

Good luck with yours....

Bob

Hey on the bright side ...
 

... I'm giving a mechanic NEAR YOU a lot of experience with A8s LOL

Seriously, tho, his main tech was at an Audi dealership for years before he came here so I trust their basic and advanced skills with the 4.2 etc.

Yes .. a straight-cut gear whine or perhaps a ball bearing in it's death rattle.
 

That would be a good pair of descriptions... whirring, metallic whining .. not a grinding or shrieking.

I was hoping for the bearings in the alternator or AC compressor would be the cause of the noise.

As for the volume.. when you pull into your garage, it's loud enough to scare the crap out of you. Plainly audible from inside with the windows closed .. not soft ..

Re: Same here, jerky when cold and slight whine in first.
 

Yes .. it was jerky in first when cold, here, as well.

Give me a call if you need parts or any help.