09 C6 A6 Transmission Slamming & Dropping Out

[Lurchy22]

Hi, I have a problem with my transmission for a few years now and it has progressively gotten worse. If I am coasting or driving in the 25 to 45 mile per hour range and punch the accelerator, my car will slam really hard into gear. You can hear it and feel it. Sometimes it will perform as normal and continue the acceleration but other times it will shutter and it has even completely dropped out of gear before. The transmission is being looked at for the third time. The first time they thought it was a relatively simple fix, the second time, they upgraded the Audi software and replaced a part.

Is this something that others have experienced?
Could my APR stage 2 plus tune have anything to do with it?

Thank you!

[Audibot]

Last time fluid was changed?

[csmith418]

Semi-Related, my car has been experiencing the same issues. I have a slight transmission leak and am low on fluid. I was going to top it off, but have been trying to find a diy guide on where the fill port is and how warm the transmission should be when fluid is added. For reference I had the fluid changed about 25,000 miles ago, but I think I have lost just enough to cause the rough shifting. I was just hoping to do this until I have more team to fix the leak itself. Any advice?

[Audibot]

Should be the same steps as in this B7 DIY (below). There's also a fill plug on the side that can be used too (it's what I used when I did mine years ago). I'd locate the leak first--if it is the pan gasket, then that's just part of the process.

https://www.audizine.com/forum/showt...TF-Replacement

Keep in mind the fluid nowadays is ZF Lifeguard 8. I didn't have good luck myself mixing it with the old Lifeguard 6 (in my experience, made the fluid too watery and it started slipping). Instead I had it drained and filled (3x to make sure all old fluid was removed) with Redline D4.

[Lurchy22]

I imagine that the transmission shop would have picked up on it if it was a fluid issue since this is the third time they've worked on it. I should be getting an update from them tomorrow or Friday.

When it slams into gear, it's pretty violent. It also only happens in that range of speed. I don't know if that is in line with what would happen if the fluid were low or if it would be across the whole spectrum of gears.

[EuroxS4]

Sounds like a transmission issue internal of the trans could be caused by dirty/low fluid or the torque converter lock up clutch is no good. But normally you would have faults stored in the TCM. Any competent shop can check for faults also check clutch pack engagement via MVB.

[vasekanx]

had this problem on my A6, did tranny fluid service first.. it helped but didnt fully solve it. Just recently did Carbon Clean and full Throttle Body Replacement and my stage 2+ Unitronic Single Pulley Flies and Drives as smooth as Stock.

- - - Updated - - -

had this problem on my A6, did tranny fluid service first.. it helped but didnt fully solve it. Just recently did Carbon Clean and full Throttle Body Replacement and my stage 2+ Unitronic Single Pulley Flies and Drives as smooth as Stock, No more banging the tranny. Maybe this will help you.

[Lurchy22]

Thanks for all the feedback. They said there weren't any faults in the system. I wish I could recall the part they replaced the second time it was in. I had the carbon cleaning done under warranty about four years ago. What did the throttle body replacement cost? Money is a little tight right now.

[christianb5s4]

My car can have this happen too in very specific circumstances but I never lose gears, and mine has a brand new filter and OEM fluid 5k miles ago. Frankly these transmissions have never been know as the smoothest transmissions out there and definitely have their shifting quirks likely due to Audi's software.

Did anyone notice a tangible difference after updating the transmission software to the latest version?

[rrated]

I had this exact same issue and it was a rear motor mount that needed to be replaced.

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[christianb5s4]

You mean the transmission mount?

[rrated]

Possibly. I have to look at my records, the tech changed it when he had the motor out for my timing chain replacement

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[christianb5s4]

I had mine done, it made no difference. Motor mounts were verified as good at the same time.

[Lurchy22]

So far they are going to replace the bushings and possibly the valve body. I did have motor mounts replaced under an insurance claim last year and that didn't make any difference. I should get an update from the shop in the next couple days.

[christianb5s4]

Did you ever scan for transmission specific fault codes?

[Lurchy22]

Yes, they did and what was interesting is initially there weren't any codes but as they dug deeper, a few came up. I am going to get a call from them on Monday with an update. Is it possible that the stage 2 plus tune could have impacted the transmission?

[C6Avant]

Don't let them swap out the valve body right away. Those things are very expensive. Many times it is just the mechatronic sleeves and solenoids, not the actual valve body. The 6HP19 tranny was used in a TON of vehicles and there is a lot of information out there about this simple service. Solenoids are a couple hundred bucks and the sleeves are cheap.

[Lurchy22]

Thanks for the advice. I'm almost positive they did replace the valve body last year when it was in. I should get an update tomorrow and will post what the fix was in case anyone else has this issue.

[Lurchy22]

Got more information. The first time it was in, they replaced the solenoids. The second time, it was the valve body and also some electrical related to programming. This time, it's some bushings and possibly a couple clutches. He said they've had to dig in a bit deeper than they thought it but it's all covered under warranty for the work they did before. I should get it back Friday afternoon.

[Robokam]

I was having similar issues in my previous 2010 C6.5, mainly the 2nd to 3rd gear shifts. It would give the hard clunk and sometimes would stay in 3rd gear until I would restart the car and it would be gone. I was at about 177k miles on the car. I loved the car but didn't want to keep putting $$$$ into it. I knew eventually it would be something else going bad on a car with that many miles so I got rid of it. I had a previous 2001 BMW E39 that was also staring to give me tranny issues at about the same mileage that I really loved too but German cars with high miles means a lot of money. I'm now driving a 2019 Honda Accord Sport 2.0T with a 6 speed manual for a change from an auto tranny. The Accord is about the same length as the C6.5 A6.

[christianb5s4]

The C6.5 is actually a pretty long car. I'm looking at newer Cayenne GTS or Turbos as a replacement for the C6 and the Cayenne is actually a few inches shorter.