Transmission fluid flush

A6 All/ S6 All
#1

Had my car over at Chicago Performance and Tuning for my 55k service (new plugs, oil, filters, etc.).

While there, had new front 355mm rotors and Carbotech AX6 pads installed. Car was raised up a little bit too to address a rear rubbing issue. Got rear sway modified so it could be reverted back to stiff setting without grinding on axle. Aligned and balanced. Decided to get a transmission fluid flush and replace as well.

All I can say is massive improvement. It feels like a new car.

Transmission service was undoubtedly the best part. Not only are shifts quicker, they are perceptibly smoother. No more clunkiness or hesitation in any gear. Everything feels much more crisp, instantaneous and direct. I would absolutely recommend the service for those with the ZF-6 speed. I was worried that I was just throwing money away and would not see any tangible beits but I was pleasantly surprised. Hopefully one day CV can work his magic and perfect this transmission.

Fingers crossed, APR has the updated C6 tune ready by fall and I’m able to post up some faster times before winter.

On a side note, there was a 991 GT3 and 991 GT3 Cup car there. Both white. Same owner. I’d be quite content with one.

#2

Great info!

I’m hoping we will see a TCU tune for the S6 this Fall from CV. It would be great if the work done on the S6 trans could also be applied to the A6 3.0t transmission. People rave about the JHM/CV trans tune for the A4 2.0t.

So it is something I am really looking foward too on the S6, especially since the S6 trans has a number of interesting quirks that need to be resolved… like randomly and suddenly shaking the car with a huge THUD, chirping the tires, and making you feel like you got rear ended by a Mack truck, when you decide to roll away from a stop sign.

Fun stuff!

#3

about 1000 miles ago, I got a “service in 1000 miles” note on my dash… the miles gradually reduced as I kept driving, and now it says to service now. Car has about 103k miles. Anyone know if this is something serious, or is it just a general reminder that the car hasn’t had any major service done in x miles? I know I’m about due for some work, I’ll throw in a transmission fluid flush while I’m at it, thanks for the heads up

#4

From what you’ve stated, nothing serious. Just the recommended service interval. Gets reset in vag com.

#5

great post OP i saw the same improvements. I know Audi says lifetime but the transmission seems to like the fluid change.

and I have the CV tune on my s4 for the transmission. It really makes for a better driving experience when your transmission is like a dsg

#6

Now that any serious issues in my S6 have been handled, I’m shifting my attention towards the transmission. I’m really just not very happy with my trans - ZF lurch, slow shifts, seems like it takes way too long to fully grab a gear, and launches (even with traction control completely disabled) leave a lot to be desired, seems like the car doesn’t really start accelerating quickly til it’s hit 10mph or so, when it should really be kicking me back in my seat as soon as I hit the throttle. I’m ready to throw down $1000-$1500 to get some improvement from it, what do you guys think I ought to do?

I’ve been reading as much as I can, and this article from a BMW forum seems like a good start: http://www.bmwlogicseven.com/?p=3738

Between that page, and what I’ve read on the forum, it seems like the best order to handle an underperforming zf6hp26 trans is this:

  • Fluid flush
  • TC rebuild or replace
  • Trans Oil cooler replace
  • check/fix any coolant leaks (My car doesn’t seem to have issues here)
  • Mechatronic adapter seal
  • Other rubber pipe seals
  • Solenoids

I sort of just want to do as many of those line items as I can all at once, but is it better to just try one thing at a time? Sounds like some of those items, if they develop problems with age, could ruin the trans, so maybe some preventative maintenance is in order? What say you?

#7

Even before flushing fluid, try a throttle body adaptation in vcds and see how it feels. It helped smooth out shifts in my car. It seems to only be a temporary fix but I do it every couple of months and always notice the difference. In fact, I do it right before making runs at the 1/4.

#8

Yes throttle body adaption should help. Also check the box code and maybe see how that stacks up vs the updated box code guys