S6 V10 Gearbox issues (C6)

[dele]

Hi all, you might of seen in my readers cars thread but I'm having some intermittent issues with my gearbox

Sunday morning I got into the car and put it into R to leave my driveway

Nothing.

Reverse didn't engage, the car didn't give an error, it just sat in R but let me rev the car as if it was in N, this happened twice before R finally engaged and I could move off the driveway only to put it into D and have it do the same thing to me, nothing

Once it was moving, it didn't give me any more trouble and its been fine for a few days, this morning? it did the same routine.

Theres no nasty noises, no burning smells, its the strangest thing

Anyone out there had this issue on their C6 S6? I hear its a problem on the older C5 but they have a different gearbox

[Dr G]

Oddly, an old A8 did this to me yesterday. 3.0 TDI with 180ish on it.

Reversing up a very steep drive I stopped to look for traffic crossing then went back on to throttle. As I came off the brake the car rolled forward just a shade and the engine revved but no drive. Back on brake, tried again, same problem (revs and no movement). Put it back into neutral then into reverse and the problem was gone. No smell, warning lights or any strange behaviour otherwise.

I wondered if it might be some sort of safety system as the road was so steep. Couldn't reproduce it and not something the owner has complained about.

[dele]

Dr G said:

Oddly, an old A8 did this to me yesterday. 3.0 TDI with 180ish on it.

Reversing up a very steep drive I stopped to look for traffic crossing then went back on to throttle. As I came off the brake the car rolled forward just a shade and the engine revved but no drive. Back on brake, tried again, same problem (revs and no movement). Put it back into neutral then into reverse and the problem was gone. No smell, warning lights or any strange behaviour otherwise.

I wondered if it might be some sort of safety system as the road was so steep. Couldn't reproduce it and not something the owner has complained about.

I'm going to keep my eye on it and have my GoPro in the glovebox at all times to record what's going on if it starts again

For what its worth mine is a 58 plate with 42k miles on it, both times this happened the car was on level ground

Edit:

Another chap has suggested "topping up" the fluid level in the transmission but I was under the impression these units are "sealed" and topping up any fluid is a big no-no?

Edited by dele on Wednesday 6th August 13:00

[ivaylo]

They are not sealed and it's worth changing the oil and filter at ~60k miles depending on use. You need ZF Lifeguard 6 ATF for it.

[Adrian E]

It would be well worth checking the fluid level correctly (requires a wheels free vehicle lift and a cold engine and box to start with, as you need to check the level at a set temperature range which is really quite low)

Ignore the 'advise' that the unit is sealed for life, or you will eventually find out the 'life' of the unit when it fails spectacularly! Check with marque specialists and they will advise on a change interval for fluid and filter if you plan to keep the car long term.

The 6 speeders are more reliable/long lived than the 5 speed but still require maintaining

[dele]

Thanks all,

I'll see how it goes for the rest of this week and look into getting it booked into somewhere for a check up

Incidentally, anyone got any recommendations of specialists in the Herts area? Or am I best off just going main stealer for this?

[bimjim]

dele said:

Thanks all,

I'll see how it goes for the rest of this week and look into getting it booked into somewhere for a check up

Incidentally, anyone got any recommendations of specialists in the Herts area? Or am I best off just going main stealer for this?

I'm planning on getting mine booked in for a fluid/filter change here - Stephens Engineering

I've not used them myself before, but they seem to have a good reputation.

[Dr G]

Adrian E said:

It would be well worth checking the fluid level correctly (requires a wheels free vehicle lift and a cold engine and box to start with, as you need to check the level at a set temperature range which is really quite low)

Ignore the 'advise' that the unit is sealed for life, or you will eventually find out the 'life' of the unit when it fails spectacularly! Check with marque specialists and they will advise on a change interval for fluid and filter if you plan to keep the car long term.

The 6 speeders are more reliable/long lived than the 5 speed but still require maintaining

ZF's advice and Audi's differ significantly. Were it my own personal car I'd follow ZF's and change it.

[Adrian E]

Indeed they do - I got good advice speaking to ZF in the UK about recommended intervals. Basically although Audi state sealed for life, if you read the small print of the manual or speak to their technical folk it aligns slightly more to the ZF line. Basically if the car is subject to 'high load' usage, which can amount to lots of town work, or full bore launches, they will suggest you change the oil.

Getting mine changed on the S8 at about 8 years but under 40k miles (from memory) resulted in much quicker take up of drive when going from D or R or back, plus sweeter upshifts. It was never bad, but noticably smoother after. Did the same on the A6 3.0 QS and it made no difference at all, which probably was down to the lower power output having placed less wear on the oil. Still glad we changed it as when we sold the car recently with 70k miles on it the box was still as good as when we bought the car at under 20k miles

[Dr G]

Sounds a lot like the advice on service intervals; everyone stringing them out to 20k miles and ignoring the guidance on use.

[dele]

A little update

My local Audi wont change the fluid in the gearbox because its a sealed unit and doesn't need changing

Wont be wasting my time with them ever again then

[Adrian E]

If your in Herts as per your profile then check out Stephens Engineering, who are ZF approved I believe

http://www.stephensengineering.co.uk/

[bimjim]

Adrian E said:

If your in Herts as per your profile then check out Stephens Engineering, who are ZF approved I believe

http://www.stephensengineering.co.uk/

I had my ZF 'box serviced there last month - They were friendly, helpful and all seems to be well since.

That was a preventative move by me though, rather than hoping to fix something.