Harsh downshift from 2-1, occasional 3-2 (OB5/DL501, S-tronic)

[pixo.sk]

Hi guys,

I am quite depressed by this so seeking some help on forums.

DL501 harsh downshift in 2014 A6. Occasional 3-2 when specific conditions are met and almost every 2-1 once hot.

No errors, which drives me mad.

My fixing procedure to date was as follows:

1. Changed oil and both filters, adaptation (still harsh)
2. Changed all solenoids in mechatronic, new harness, adaptation (except those in “tower” related to forks) (still harsh)
3. Changed dual-clutch, flywheel, all gaskets, new bearing - now still waiting to finish clutch point calibration within adaptation (100km driven, however already harsh)
4. This only happens when the engine/transmission gets hot. Its worst when hot and agressive stop is made at the same time.

Otherwise its silky smooth including all upshifts 1-7 and downshifts 7-3. No kicks at stop in D or R. Every gear follows order as it should, no skipping.

I am now waiting for Audi Dealer to get an software update if available (not sure if they will do it but I have only VCDS/VAG-COM). According to this article it may help but does not makes sense for me as everything has already been changed (https://www.transmissiondigest.com/shock...-release/#)

As I am a little bit skeptic this will help I am proactively looking for next steps I can take. Any ideas please?

Its my own car in totally superb technical shape at 225 000km. No issues from new until approx last 1000km when kicking starts.

Thank you for any advice.

Transmission identification data:
Part No SW: 4G5 927 156 HW: 0B5 927 156 K
Component: 0B5 30 TDIRdW H02 0003

[Hurricane17]

No clue what I’m talking about with these cars, but I have seen a bad motor mount do this on other cars. Allows the transmission/driveline to flex just enough that it feels harsh downshifting. Though this also occurred on upshifts as well, and didn’t matter much about being hot or cold. But it’s probably worth checking out anyway.

[joserod92]

try the vcds adaptation http://wiki.ross-tech.com/wiki/index...rbox_(DSG/0B5)

[pixo.sk]

No clue what I’m talking about with these cars, but I have seen a bad motor mount do this on other cars. Allows the transmission/driveline to flex just enough that it feels harsh downshifting. Though this also occurred on upshifts as well, and didn’t matter much about being hot or cold. But it’s probably worth checking out anyway.

Thanks for heads up, however with these fixes, when the transmission was out I also did timing chain kit and other stuff with engine out too. The whole drivetrain was aligned as it should be.

- - - Updated - - -

try the vcds adaptation http://wiki.ross-tech.com/wiki/index...rbox_(DSG/0B5)

Was done in each step (sorry I forgot to mention in the first step - post edited). Thank you anyway.

[joserod92]

Thanks for heads up, however with these fixes, when the transmission was out I also did timing chain kit and other stuff with engine out too. The whole drivetrain was aligned as it should be.

- - - Updated - - -



Was done in each step (sorry I forgot to mention in the first step - post edited). Thank you anyway.

Is the car tuned?

[pjekar]

Definitely following - I’ve got somewhat of similar problem. Anytime I drive for 20-40mins, any downshift from 2 to 1 and less noticeably from 3 to 2, it feels very harsh and jerky. No tune here.

18’ S7
Sent from my iPhone using Audizine Forum

[joserod92]

Definitely following - I’ve got somewhat of similar problem. Anytime I drive for 20-40mins, any downshift from 2 to 1 and less noticeably from 3 to 2, it feels very harsh and jerky. No tune here.

18’ S7
Sent from my iPhone using Audizine Forum

Yeah the dl501 in the S7 or S6 is very jerky compared to say a S4.

[cardioS6]

2014 S6 here, after i did IE TCU tune sometime ago, i began to experience this too, downshifting from 2-1 was very harsh, i tried to change between the TCU files but, it didnt change nothing, when the transmission gets hot, it starts to do this harsh 3-2 and 2-1 downshift, initially i talked to IE and they send me a "revised" file that eliminated this for some weeks, now its doing it again

[pixo.sk]

Is the car tuned?

no it is not

[pixo.sk]

I gathered some new info:

Audi Dealer is not able to do an update - even if available - until the part has an error code. Which I don't have any - so they can't help. Therefore I may try to find some independent to do an update.

From a transmission specialists in Poland, I was told that if I still have a problem after change of solenoids and dual clutch, it may be the oil pump and bearing for K2 shaft. As the oil pump can't keep up the pressure for new dual clutch, thats the problem.

For me that make sense - oil pump can be an issue - as when it gets hot, the viscosity of oil is change and the pump can't keep up. But I didn't find this issue on any forums and I research the whole internet. Not a single post. And this should be Gen 2 DL501 transmission so I would not expect that - maybe with first generations from 2011. The bad news is that pump is another 500 EUR + 50 for bearing and transmission has to go out once again. And I didn't count the labour. :(

Will see if anything else will pop up - may try to do an software update first if I find somebody, then pump.

[joserod92]

I gathered some new info:

Audi Dealer is not able to do an update - even if available - until the part has an error code. Which I don't have any - so they can't help. Therefore I may try to find some independent to do an update.

From a transmission specialists in Poland, I was told that if I still have a problem after change of solenoids and dual clutch, it may be the oil pump and bearing for K2 shaft. As the oil pump can't keep up the pressure for new dual clutch, thats the problem.

For me that make sense - oil pump can be an issue - as when it gets hot, the viscosity of oil is change and the pump can't keep up. But I didn't find this issue on any forums and I research the whole internet. Not a single post. And this should be Gen 2 DL501 transmission so I would not expect that - maybe with first generations from 2011. The bad news is that pump is another 500 EUR + 50 for bearing and transmission has to go out once again. And I didn't count the labour. :(

Will see if anything else will pop up - may try to do an software update first if I find somebody, then pump.

Try contacting tvs engineering first, they have dsg files for every case.

[last_mile]

Facing similar issues with my 2013 A6. Following your thread.

[Audibellybutton]

When i got my car it was apr stage 3 without a tcu tune. The down shift from 2 to 1 was rough the car was really jerky overall. the original owner told me if you get a tcu tune itll fix it. I took his word for it, as i was already planning to do that. That was the first thing I did, it resolved the issue completely. Hope that helps

[pixo.sk]

No new update yet as I have didn't time to arrange things, however one new strange finding:

On S the occasional 3-2 downshift did not hapen ever. In D in certain conditions like temperature, quick stop, etc. it happens especially when oil is hot. In S never, event when is hot. However 2-1 still present even in S.

[hunadler]

No new update yet as I have didn't time to arrange things, however one new strange finding:

On S the occasional 3-2 downshift did not hapen ever. In D in certain conditions like temperature, quick stop, etc. it happens especially when oil is hot. In S never, event when is hot. However 2-1 still present even in S.

Hy , any update ? Im suffering this problem too…

[pixo.sk]

Hy , any update ? Im suffering this problem too…

SOLUTION

Hi guys, I am very sorry you didn't hear from me sooner. However, it was the craziest month in this year for me. Personally and at work.

Finally looks like the problem is solved and the last issue was a damaged gasket on valve body as was suggested. Image from my issue attached. I must missed that first time.

I also managed to up to date SW version of TCU as mentioned below.

Few kilometres at oil temp approx 90 degree celsius, finished adaptation and 2-1 didn't kicked once.

So just to sum it up for anybody that will be in the same boat:

- new oil, both filters, gasket
- change all the solenoids at the bottom of the mechatronic
- changed dual clutch pack, flywheel, bearing
- software update to v 005 (this alone solved occasional 3-2 harsh downshift, and the transmission*does not select D1 until I am at complete stop now)
- changed the mechatronic gasket at valve body
- adaptation

Thank you for all your advice. Really appreciated.

[Yeoman]

sounds like a transmission rebuild.. how much did that set you back?

[Akakios]

https://www.youtube.com/watch?v=ysAooa0USjk

With this plus my motor mount replaced with calibration on the 4.0T, I have a silky-smooth drive train now.

[last_mile]

Wonderful. Glad that you sorted it out in the end, and thank you for taking the time out to report back.

I am also facing exactly the same issue. Do you think changing the mechatronic gasket alone would have fixed the issue?

[pixo.sk]

sounds like a transmission rebuild.. how much did that set you back?

Not almost, but lets call it that that critical parts were rebuild, especially mechatronic unit.

I sourced parts myself to save some money but with labour included it was like 4000€.

Along with that I have already changed parts in the engine like the timing chain, tensioners, water pump, belt, cleaned DPF, etc.

All in all 5500+ EUR total. I am bleeding :)

- - - Updated - - -

https://www.youtube.com/watch?v=ysAooa0USjk

With this plus my motor mount replaced with calibration on the 4.0T, I have a silky-smooth drive train now.

This is more like, adaptation or par of it which can (and was) done by me several times in the process via VCDS (VAG-COM).

[pixo.sk]

Wonderful. Glad that you sorted it out in the end, and thank you for taking the time out to report back.

I am also facing exactly the same issue. Do you think changing the mechatronic gasket alone would have fixed the issue?

You will see once you will open it. There are so much that can go wrong witch mechatronic that I am not surprised that authorised dealers choose to change it for a completely new part (but it is expensive).

In your case I would start with stripping of mechatronic unit and check the gaskets. I assume nobody from us has a machine for correctly checking solenoids so I recommend to change at least with the main pressure valve/soleonid and cooling valve/solenoid along with the gaskets or the whole repair kit with the board.

Then try it out and see if the problem persists. I also strongly recommends to make a full adaptation after any mechatronic repair.

[Akakios]

Not almost, but lets call it that that critical parts were rebuild, especially mechatronic unit.

SNIP

- - - Updated - - -



This is more like, adaptation or par of it which can (and was) done by me several times in the process via VCDS (VAG-COM).

Very much so, I only had an ODB11 so I was not sure if it would work entirely in the app and stumbled across this. I do not know if it does it entirely like the VCDS does, but it sure felt like it. Figured it might be helpful for people searching in the future if they want to try it before breaking out the VCDS.

[pjekar]

When you mention TCU tune software update - which TCU tune are you referring to? SRM?


Sent from my iPhone using Audizine Forum

[vrod]

This trans is the only thing i hate about my S6. Had the same issue but lucked out and got a complete refurb trans for 1500€. Still looking to rebuild the old trans, thanks for the information!

[1nS4ne]

I am experiencing the exact same issue on my 2016 S6. I just replaced both filters and the fluid. I installed the mechatronics repair kit while replacing all lower solenoids and swapping around the upper shift solenoids to see if it changed anything (all solenoids passed the Ohm check though). TCU is on the latest software. And then ran through the adaptations, but unfortunately it still has the rough 2 > 1 downshift you describe when coming to a complete stop.

I was about to buy a completely new unit, but this has given me hope for a cheaper solution.

Can I ask you where you got the replacement gasket from?

Also, when you opened the valve body up to replace the gasket, did everything stay in place? I am worried about splitting the halves and having something fall out and I have no idea where it goes back. If you have any diagrams that assisted I would greatly appreciate those!

[pixo.sk]

Hi Guys,

Once I have figured our harsh downshifts a problem with rough upshifts came in.

The major new issue is that now I have jerk when shifting 1-2, and definitely when shiftinl 5-6. To some extent its not silky smooth on every upshift (but again, only sometimes). Depends on a situation, it is not always present which is strange. Sometimes when hot, sometimes also when cold.

However it is always definitely noticable for me and not smooth as a butter.

Options I see (not sure if correct):
- new oil pump
- new TCU
- or something else (not sure what)

I am completely lost and already invested a lot into this. A completely new mechatronic unit is also an option - however not financially rational right now and I also don't have an option to "try" another one to determine if that part exactly is still the issue.

One thing to note:
The issue with upshifts are mostly pronounce when acceleration is steady and uniform. However if I lower the pressure on pedal right before it comes to a shift, that change itself is much much smoother. Feels like pressure related thing. However this is just a basic driver observation.

Thank you for any tips.

[Fsantana]

do you have the part number ??? for the gasket plate???

[vrod]

This trans is the only thing i hate about my S6. Had the same issue but lucked out and got a complete refurb trans for 1500€. Still looking to rebuild the old trans, thanks for the information!

And here I am again, with the new transmission doing the same f*cking thing as the old one. 🤬

Is there some new info regarding these issues? A person suggested me a “034 Motorsport transmission mount” solution which should apparently fix some things. TVS also has some transmission software which apparently solves it. Do people have experiences with these 2 solutions?

[1nS4ne]

And here I am again, with the new transmission doing the same f*cking thing as the old one. 🤬

Is there some new info regarding these issues? A person suggested me a “034 Motorsport transmission mount” solution which should apparently fix some things. TVS also has some transmission software which apparently solves it. Do people have experiences with these 2 solutions?

I had the transmission mount and it definitely did not fix the issue.

I also emailed TVS regarding this and they said their software would make it less noticeable, but I don't recall them saying it would completely solve it.

[Emejcz]

SOLUTION

Hi guys, I am very sorry you didn't hear from me sooner. However, it was the craziest month in this year for me. Personally and at work.

Finally looks like the problem is solved and the last issue was a damaged gasket on valve body as was suggested. Image from my issue attached. I must missed that first time.

I also managed to up to date SW version of TCU as mentioned below.

Few kilometres at oil temp approx 90 degree celsius, finished adaptation and 2-1 didn't kicked once.


.

Hey. Did this kick from 2/1 once gearbox is hot stopped right after replacement of that big mechatronic gasket?
Was only that gasket replaced (there are two - top ant bottom) or also other gaskets and orings were replaced?

[blubaru]

Bump. Having this issue after DSG service with febi “OE” fluid change. I’ve done the adaptation 3x and I’m about to lose my mind with the 2-1 lurch / rev down. Car feels like it is holding 1st too “tight” if that makes sense, it moves off the line like a normal automatic when letting off the brake. Also hearing some noises when slowing down in 2nd, similar to the distance sensor calibration. Any chance this is fluid related or does it sound like mech unit going out weirdly after the service / adaptation?