Transmission jerky

438593839

MEMBER
2013 AUDI A8
4.0L
V8
TURBO
4WD
AUTOMATIC
90,000 MILES

Hello experts,

I’m having an issue with my car listed above (A8L 4.0T’s) transmission (ZF 8 speed). First of all, it has a hard up shifting from first to second gear. It feels like the transmission doesn’t shift quick enough that the power stops for half second. Then second to third occasionally produces hard shifting but hardly noticeable. All other gears works fine when up shifting.

Then when slowing down to a stop, the fifth, fourth, third, second downshifting are also hard. Feel like extra brake is applied every time it changes gear. Then occasionally it shudders right before going to a full stop.

I’ve had transmission fluid changed but didn’t help. I also have slightly worn engine mount that I can feel some vibrations at lower RPM. Could weak engine mount cause the transmission to shift hard? Or is it something else like the torque converter etc?

Any information will be helpful and appreciated.
Thanks

8 Replies

JACOBANDNICKOLAS

MECHANIC
109,709 POSTS

Welcome to 2CarPros.

As far as the motor mounts, that shouldn't cause this. Have you had the vehicle scanned for transmission diagnostic trouble codes? These vehicles are extremely temperamental and can be difficult to work on. A hard shift can be related to several things. Transmission line pressure issues, shift solenoids, torque converter issues, issues with the transmission control module (TCM) or a simple wiring issue. Since the vehicle has an aluminum body, they often have issues with poor grounds due to corrosion.

Let me know if you had it scanned. Also, this isn't one that can be checked at a parts store. It will need to be scanned by a shop that has the proper equipment.

If you can, let me know if any diagnostic trouble codes are found.

Take care,
Joe

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Friday, August 30th, 2019 AT 9:44 PM

438593839

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Hi Joe,

Thank you so much for the reply. And I apologize for responding late. So I finally got a chance to take the car to a transmission specialist and ask them to check and scan it. They got back to me later saying that they had not found any fault code nor any obvious faulty parts in the transmission. However, they did tell me that it seemed like Audi had a TSB regarding TCU software updates; thus they suggested me to contact the dealership.

So do you think it could be a software issue that causes jerky shifting or it is more likely to be caused by damaged/malfunctioning parts within the transmission that can only be identified by disassembling the transmission (which the shop hasn't done yet)?

Thank you again for the help!

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Thursday, September 5th, 2019 AT 8:55 AM

JACOBANDNICKOLAS

MECHANIC
109,709 POSTS

Welcome back:

Honestly, yes it could need reprogrammed, but I checked and don't see any technical service bulletins related to shifting. I attached a picture. It shows what transmissions TSB's are active.

You know, I owned a 2008 and my brother presently owns a 2012. Both cars have a crazy downshift that is noticeable. When coming to a stop, both clunk into first. His only has 40,000 on it. When I sold mine, it was at 150,000 miles. It acted that way from the time I got it at 30,000. Is that what you are feeling? Also, has anyone added transmission fluid to it? The wrong fluid can cause a rough shift. Also, I realize you took it to a transmission shop, but did the check the transmission fluid level and condition? The transmission needs to be a certain temp and the vehicle running when you remove the level plug from under the transmission. If it isn't running, fluid will go everywhere. I only ask because it is a pain to do and if someone doesn't have the ambition, they won't do it.

Let me know.

Joe

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Thursday, September 5th, 2019 AT 7:33 PM

438593839

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Hi Joe,

Thanks again for the response. The TSB regarding TCM update is Group 37 #16-69 (see pictures). It was released on September 30, 2016. Yet I didn’t notice such shifting issues back then; it’s only a recent thing. But it seems like the TSB addressed the similar issue I’ve experienced so I’ll give it a try. I’ve scheduled for dealer visit next week so I’ll report back if the TSB helps or not.

Regarding the fluid, the shop did tell me that they checked fluid level as well as temperature but found nothing. I’m not 100% sure if they did it the correct way. But few month back I had a transmission flush done which was supposed to replace all the old fluid with new one (I used ZF Lifeguard 8). So I’m confident it shouldn’t be because of low fluid.

Anyways, thank you again for all the help! I’ll report back if the TSB solves the problem. :)

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Thursday, September 5th, 2019 AT 8:10 PM

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