My auto is slightly hunting at 50mph (top gear at 1200-1400rpms) when on minimal throttle... is this normal?

It's usually as I hit a gradient... then the revs raise and fluctuate +- 200rpms with no change in throttle or gear.

Is this the start of a failing torque converter or will an auto box flush sort it.

Cheers RRS gone
Audi SQ5...Gone Audi Q7 S-Line 240 3.0TDI Gone
Audi A6 Allroad Sport 270 3.0TDI

Update:

Spoken to dealers and they've suggested the bush at the base of the gear selector may be worn...

Need to try to replicate the issue in command shift, and if it doesn't, then that's the culprit... otherwise it's got to go in... RRS gone
Audi SQ5...Gone Audi Q7 S-Line 240 3.0TDI Gone
Audi A6 Allroad Sport 270 3.0TDI

It's the gearbox fluid .... Mine was chronic before having it megaflushed by 4tech a couple of weeks back , I also had judder on acceleration ... Both symptoms totally disappear after the flush

I'd suggest getting a Glycol check on the gearbox oil done 1st, to save wasted money and time. If there is no Glycol contamination, the there is a high chance that the megaflush/double fluid change will work (approx £300).

If there is Gycol, then it becomes very expensive as I found out (approx £3,000). It was covered mostly by the warranty and then some offset by the garage as it took them 6 weeks to sort and their general service was shocking!
Although they did give me a brand new Jag XF as a 'courtesy' car so that I left the showroom quietly.

Good luck!

Mark

Thanks Mark.

Maybe a stupid question, but what would be the circumstances of Glyco beoing in the gearbox oil? RRS gone
Audi SQ5...Gone Audi Q7 S-Line 240 3.0TDI Gone
Audi A6 Allroad Sport 270 3.0TDI

Not a stupid question at all. The explanation as I understand it is that the oil in the gearbox is cooled by being passed in to an oil cooler in the main radiator. The elment in the radiator can fracture/crack, this means that coolant from the radiator leaks in to the oil that is being circulated from the gearbox to be cooled, which causes the glycol contamination.

The symptom for me was as you describe, the revs bounce because the Torque Converter in the gearbox slips, due to the contamination. The constant slip, the torque converter, which is why it was so costly to get put right. Ultimately the torque converter was replaced, the gearbox 'refurbished', oil filter cooler thing replaced, new gearbox oil (expensive stuff!) and replacement coolant.
It's a known problem/side-effect of the ZF geabox design.

I noticed that I had to top up the coolant a couple of times in a short period, which meant the problem for me was at an advanced stage. The garage didn't diagnose it correctly in the 1st place, which is why i was able to... errrr... negotiate with the Dealer Principle on the money I paid and got a nice courtesy car whilst mine was away.

There are a couple of possibilities for the problem you describe, mine was the worst case scenario. Hopefully yours is one of the lesser issues, which is cheaper and easier to resolve.

Cheers,

Mark

 RRS gone
Audi SQ5...Gone Audi Q7 S-Line 240 3.0TDI Gone
Audi A6 Allroad Sport 270 3.0TDI