2008 A6 Transmission

[fishguy]

Hello,

I have a 2008 A6 Avant S-line. I have about 130,000 miles on it and I’m looking for advice. Have been dealing with intermittent transmission issues for several months now. It would light up all the gear selector lights and go into limp mode when I would accelerate hard or sometimes just going around a hard corner. I don’t have a vag com but I do have a blue driver code reader/clearing tool. It would give me a P2704 sometimes. I would clear it out and go on my way. Or sometimes it would just reset itself when it was turned off and on. I did have the transmission serviced by a reputable independent back in December. That didn’t fix anything. I have reset it probably 30+ times and continued on my way each time. About a week ago, this happened again, but, I was in heavy traffic and had to accelerate hard in limp mode in order to get safely to the shoulder. And when I reset it, it wouldn’t drive at all...

Now I have the car up on a lift, when it is running and you put it in any gear nothing happens, the shift handle moves and the appropriate gear indicator lights up on the dash, but the wheels don’t spin... unless you move them by hand, then they spin freely and the opposite wheel spins the other direction. Front and rear are the same. And with my blue driver code reader, I am not getting any codes now. I was looking into putting a used transmission in and was thinking if we transferred over the Transmission Control Module (if that’s possible?) maybe that it would work?

Anyone have any advice, ideas or experiences they can share with me?

Thanks in advance.

Tim

[cal3thousand]

First question for a car that age with Transmission issues: Have you changed the fluid? If so, When and What fluid. If not, that's the major problem.

There should be no argument as to whether or not transmission fluid should be changed. Problem here, is that you may be past the point of doing it any good because that fluid is necessary for proper operation and longevity. Compromised fluid will lead to poor performance and ultimately wear (damage).

You either need 1) New fluid or 2) New transmission. I would start with the $200 fluid option as opposed to the $1k transmission option.

[fishguy]

yes, as originally stated, I had a full service on the transmission in December including the fluid and filter, and I wish it had only been $200, but it was around $1000 and did not make any difference... and drove approximately 3500-4000 miles since then

[cal3thousand]

yes, as originally stated, I had a full service on the transmission in December including the fluid and filter, and I wish it had only been $200, but it was around $1000 and did not make any difference... and drove approximately 3500-4000 miles since then

So, what does this reputable independent mech say about it? I'm assuming you mentioned to them that their $1k efforts didn't fix anything?

[christianb5s4]

First question for a car that age with Transmission issues: Have you changed the fluid? If so, When and What fluid. If not, that's the major problem.

There should be no argument as to whether or not transmission fluid should be changed. Problem here, is that you may be past the point of doing it any good because that fluid is necessary for proper operation and longevity. Compromised fluid will lead to poor performance and ultimately wear (damage).

You either need 1) New fluid or 2) New transmission. I would start with the $200 fluid option as opposed to the $1k transmission option.

Out of curiosity, where are you finding 8 bottles of Audi ATF for $200 total? That's much cheaper than I've been able to find.

[cal3thousand]

Out of curiosity, where are you finding 8 bottles of Audi ATF for $200 total? That's much cheaper than I've been able to find.

http://www.thectsc.com/catalog/6-speed-58.html

They are currently out of LG 8, but this was where I purchased it at least a year ago.

[fishguy]

I’m trying to do this without taking the car back to them. For one, it’s not drivable so it would need to be towed. Two, they’re a very busy shop and probably wouldn’t get to it for a while and will likely tell me that it needs a new transmission. I’m pretty sure it needs a new transmission as the fluid and filter change did nothing. And, I currently have the car at a friends body shop already on a lift, with labor I can afford and confidence in their ability to remove the transmission and install a used one which are readily available for reasonable cost. What I am unsure of is. Will the cars computers have a problem with a different transmission installed in the car? And is there a way around that?

[fishguy]

I’m just trying to get a straight answer. Can I install a used transmission from a wrecked Audi A6? I know that there were two types of transmissions used and I need to match the transmission codes. But is the car going to recognize it? Do I need to pull the TCM from my old transmission and install it in the new one? Will I need to take it to the dealership and have it programmed to the car? Will the dealership even do that? If needed? What will they charge? Has anybody done this? I have searched. Thank you.

[christianb5s4]

I wish I could help, I think the best way to tell is to call your local Audi dealership and provide your VIN so they can tell you the correct transmission to use. I'd have to imagine if it's the same model transmission used in your car it shouldn't need coding or reprogramming to get it working.

[sswari]

Hi Fishguy,

I did a trans swap in my 06 a6 4.2 quattro about 8 months ago.

1) You MUST have an identical Transmission tag!

2) Do not strip out the head of the triple square bolts that hold the TC to the flywheel! I can help you with how to get it out, if you do :)

The job is not particularly hard, just a lot of scary stuff. Removing motor mounts to get the starter out, then the above mentioned triple square bolts.
I found my Trans on carpart.com, over all cost, shipping included was about$1700, for a trans with 95K miles on it. The car I put it on had 100100 Miles on it. I have now put over 8K miles on it and it is running great.

PS, I did this swap on my back, on the ground.

[sswari]

Also, you will need a shop that can remove the component protection Codes. The car will start, but not go anywhere after the swap.

[fishguy]

Thank you! This is the kind of answer I am looking for. And the component protection codes concern me. Is that something that can only be done by a dealer? Where did you get yours done? And at what cost?

[sswari]

Thank you! This is the kind of answer I am looking for. And the component protection codes concern me. Is that something that can only be done by a dealer? Where did you get yours done? And at what cost?

We have a local Indy shop, that had the ability, so it does not HAVE to be a dealer, just verify with them that they can and have done it.

With towing, it was a total of $175 or something minor like that.

[sswari]

Also, that transmission is flippen heavy 300+ Pounds

[fishguy]

Thanks!!!!

[sswari]

Sure thing.

You may read a lot of stuff, like you have to drop the exhust, and yes you do, to get the "Propeller Shaft" out of the way. Be careful of the flex pipe. I only had to remove the passenger side completely, and loosen the driver side. The top trans bolts are a MF to get to. I bought this set of extensions to get to them over the top of the trans:
https://www.harborfreight.com/4-pc-1...set-61968.html

You will want to get as many replacement bolts as you can, prior to starting, the triple square bolts in most cases are single use bolts. I believe most if not all of the drive line bolts are also single use, as well as the suspension bolts that will need to be loosened and or removed.

I did have to replace a motor mount, as it was trashed when I got it out. You just never know what you might end up finding under there.

Separating the "propeller from the trans was a bit of fun also, It took a few good whacks.

Have fun, be careful and don't be too afraid, some thing seem more scary than they need to be.

I had intentions of documenting this really well, but every time I got under there, I just kept working, so not really any good pictures, but I do have fairly good memory recall of the process.

[abovo]

Thank you for taking the time to give your experience sswari. I hope I don't have to do the transmission in my 4.2 anytime soon but you never know.


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[fishguy]

So, I was able to purchase a used transmission from a wrecked vehicle (has 85,000ish miles, paid a little extra for a one year warranty that covered labor as well, it was $900 including shipping and the warranty) I had a friend with a body shop install it for me. Then had to wait for just over a week before the local Audi dealer would take it. Had it towed to them yesterday and they just called me and said they removed the component protection and that the car will not move. they are telling me that they want to do a fluid change at the tune of $1100ish and that they don't think it has much fluid in it. I know that we checked it for fluid when it was installed and it was full and looked good... I have had other situations with this dealer, and I don't trust their mechanics integrity. They will not guarantee that the "fluid change" will fix anything.

Are there any sensors or anything else that could be causing it to behave this way? ( shifts into gear, but nothing moves) On the old transmission I would occasionally get a P2704 code, the service advisor just told me that they are getting a "clutch code" on this one...

Any ideas?