S4'ed

OK, got it, thanks.
After some googling, for clarity, the gasket is a thin metal plate (silver) with soft gasket material (black) glued to both sides. This thin plate is clamped between the two halves of the valve body. Apparently, the hot fluid attacks the soft gasket material and/or the glue, which then dissolves the glue/gasket at this high pressure area between the two rectangular openings, allowing fluid and pressure leakage between these two hydraulic "circuits", causing the harsh shift problems. That hydraulic "circuit", where the black gasket material is gone, is associated with the main pressure regulator valve.

pixo.sk

Hi guys, a quick update:

The car is generally ok however I have noticed some changes over time (when the oil in the gearbox becomes hot):

• 5-6 shift: There is an intermittent issue that I cannot 100% replicate but sometimes the shift 5-6 can be rough. The issue is more noticeable when gearbox oil is hot and I push the car a little bit more to the limit - aggressive speeding (but not kick-down)
• Clunk sound: There is a little bit of *clunk* sound sometimes when idling at lower speeds only on 2nd or 3rd gear. The clunk happens and the moment when the car is idling at around 1100rpm (3.0 TDI), low speed, and press the pedal -> very slight pause with a clunk sound and then harder bite and going fwd. Again intermittent issue, hard to replicate the state.

2-1 jerk is still non-existent, and 3-2 jerk too except for once when an almost unnoticeable jerk accident happened after quite a spirited driving.

The conclusion is the car is probably still not 100% but 90% better than during the issues.

If you have any ideas about what I can check please let me know.
Otherwise, I won't touch it again until a major breakdown or diagnostic fault happens as I have already invested so much time and money already. I am officially tired of this issue

What kind of transmission fluids do you put into 0B5 exactly?
I was 100% OE before the issues, now I used Motul DCTF along with 75w/80 for transfer case. However I am not sure how it may or may not change the characteristics of transmission.

Thank you!

andrei91gl

Hello there !
I have an Audi A7 3.0 TFSI with Dl501 transmission. I have the same problem since yesterday. After a long journey , when I stopped at a red light I felt a harsh downshift after the vehicle stopped.
I thought that it would be because the oil was very hot. ( I changed the oil 15000 kilometers ago , at Audi dealer. )
Today , with cold engine and transmission , it worked like charm , with no problems. After the temperature reached again a hot temperature the downshift problem appeared again. I felt it also from D3 to D2 but only once and not so brutal.
The story seems the same like in this topic. The sw of the gearbox is at the last update since 2 years , today I made all the basic settings with Odis and the problem is the same.
What I would like to ask is a website where I can order these gaskets. In Romania I can't seem to find anywhere to order.
Thank you !

S4'ed

Valve body plate gasket kit DL501 0B5 | 08-up (maktrans.net)

hunadler

Hy,

any update? I'm suffering this problem too.
My gearbox is filled up with not original factory oil.

billmac

Hi pixo.sk,

First of all thank you so much for the extensive and detailed explanation of your journey with this pesky transmission issue. My A6 3.0T MY12 just started exhibiting this weird behavior only while hot, when downshifting from 3-2-1; a disturbing "thud", kick in the back. Not present during regular city low speed driving. But if I get on the highway for say 15 minutes or so at lively speeds, the rough downshift begins if I encounter traffic or when back in the city for regular stops. So I get the transmission must get really hot while at speeds over 60 mph (100 Km/h). Manual downshifting works fine hot or cold.

The valves gasket you mentioned makes a lot of sense. I have been driving this car since new for over 10 years now - and will continue to do so for a long long time since I love its no longer produced supercharged engine - and gaskets are not eternal. Even on sealed transmissions like this. By the way, I think you meant "lower viscosity of oil once hot" instead of higher.

Now, I have been performing the regular maintenance in my garage after the warranty expired years ago. But at my age, I wouldn't even dare to try to perform this transmission repair by myself and the nearest Audi dealer is about a 3 hours away. So, is it safe to continue driving the vehicle even at highway speeds before taking it in for a repair? I have a 6 hours drive planned for next week...

Cheers,
Bill

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.


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.

SSK1

Hi, I am exactly the same boat as you, word for word up until you replaced the main-body gaskets on the mechatronic unit (no up-shift problems). All the same parts replaced as you and I have a hard downshift from 2-1. Only thing I haven't done is a SW update, I believe I am on 006.

Can I ask, did you replace the K1 and K2 solenoids N435 & N439? (little square ones).

Thanks