Tranny sound... any input

[eanders]

I'm not that long into owning my RS6 and I am occasionally hearing a light "thud" (perhaps too strong a word) when driving in drive and the car downshifts... not sure exactly what gear, but based on my speed both times likely 5 to 4, or 4 to 3. I've never owned a performance vehicle with an automatic, and wonder if this is normal, or symptomatic of a bigger issue. All aspects of the tranny seem fine otherwise, but have some concerns over this noise.

Any input / experience is appreciated.

Thanks

[eanders]

To expand on my thread... the car has 72k miles, has been well maintained (I know for sure for the last 30k plus), and is due for its 75k maintenance.

[speedtrapped]

Invest in Vag com cable, and software. Iirc, $300.00. It allows you to scan car for trouble codes, engine, Trans, all aspects that have a sensor.
Is the thud felt?
The only thing I know and have heard usually goes on these Trans is the torque converter. Tozo may be able to identify the symptom by your description, but really it is far easier to have a tool to scan this car and down the road data log.

[eanders]

Yes, the thud is felt. It occurs after I've been getting on it a bit, and then back off the acceleration.

[4everRS]

I'd have a shop top off the fluid and see what happens.

[lswing]

+1 fluid check and cable/software...don't hammer on it for now too.

[eanders]

The previous owner weighed in...
"It has always had a thud downshifting right at 40 MPH when in am slowing down going up a hill. Chris (the mechanic) has tried to program the shifting software to eliminate it - but without success. I learned to live with it - but never learned to like it. Sorry.
To my knowledge the torque converter has never been replaced. "

I am experiencing the "thud" at the same time... up a hill, about 40mph.

[lswing]

Program the shifting software? All I've heard is the solder on chips that many of us have. Sounds like the clutch packs are shot, or TC, but really you might just need the fluid refreshed or topped off. How many miles you have the car? CEL will only take about 100 if you've got serious issues.

Different but related to fluid, my trans started slipping up a gear under heavy, was a quart short...fixed!

Edit; update your location, and hope this isn't too bad.

[G2]

Might be worth checking engine and trans mounts.

Old trans fluid could also be partly to blame (viscosity break down, degraded friction modifers). I just changed my trans fluid to Amsoil and the shifting is very smooth. It took about 4 qts to flush out all the contamination.

The TCM/ECM/DME (computers) will pick up major faults but won't account for these issues unless it's too late.

[Justin9212]

Sounds more like a valve body issue to me.

[905084]

VAG it with a 99 cent cable and VCDS Lite. Could be valve body but VAG won't catch that. Use the Tip mode to troubleshoot the gear that it shifts hard into.