Newby s8 gearbox oil

After some crappy luck, my car has been doing a tour of transmission places in the UK.

It went to Mackies for a transmission flush, which resulted in the gearbox clunking between 1st and 2nd gear.

Then, it went to Chester Transmissions to fix the clunk because Mackies said I needed a new gearbox.

Finally, it went to Stephens Engineering in Ware to check for an imaginary tranmission leak that Audi reported (it looks likely to just be old fluid before the service).

Stephens is fairly close to you and I spoke to Jason there who was really friendly and knowledgeable. They are ZF approved too, judging by the stickers and plaques all over the place.

Transmission flush ?

My apologies, I should have explained a little.

The theory goes that draining a transmission and then refilling it with new fluid only actually changes some of the transmission fluid. Dealerships have been recommending two successive changes days or weeks apart to try and help problem transmissions.

Some clever transmission folks devised a way to change 97% of the fluid by heating the fluid the required temperature, and simultaneously pumping in new fluid while sucking out the old fluid. Other forums refer to this as the 'sucky blowy pump machine'

That's what I had done at Mackies (as well as a change to LifeGuard 8 fluid) and one of the side effects is that it can bring an existing problem to the fore. I'd only recently bought the car and it looks like the gearbox was an issue for the previous owner. It was running with less than half the fluid it should have had and the filler plug was looser than expected. Driving away from Mackies presented issues for my gearbox once it had warmed up, which led to it going to Chester to have the mechatronic unit refurbished and the adaptations reset once it had been returned to LifeGuard 6 fluid.

I should add that the guys at Chester also have one of these sucky blowy pump machines but said they didn't recommend it for the S8 D3 gearbox because the electronics are too picky.

I have A8 D3 4.2TDI and it seems Audi says gearbox doesn't need servicing ever. Yet I have seen on many places that some owners do change gearbox oil anyway. So, does it really need to be done or not? My car is 2006 and closing to 120,000 miles and I assume gearbox oil has never been changed. No obvious problems, just a question: should I get the oil replaced or juts leave it as is per Audi book?

I faced the same decision and chose to have the fluid changed. My reason was because ZF, the manufacturers of the gearbox, say it does need changing. I can't remember their odometer recommendation but most people put it at 80-100k miles.

Go in eyes open though, and learn from my experience. A transmission flush can reveal hidden faults in the gearbox. It won't cause them, but if there are some lurking, it may bring them to light like it did on mine.

Chester Transmissions recommend changing the fluid conventionally without using the flushing machine owing to the picky electronics of our gearboxes. I have to admit though, that immediately after the flush, it did feel a lot nicer to drive - it was quieter at idle (didn't know how much noise the gearbox was making!) and smoother when shifting and pulling away. Now that the clunking is repaired, those benefits have stayed.

Lerd, what year is your S8? Is it a D2 or D3?

If you have a D2, there's no dispute, get the transmission serviced.

In that case, I stand by my earlier comment - a transmission service/flush is a definite must-do. Audi claim the D3 gearbox is sealed for life, but never made the same claim about the D2.

Let us know how you get on.