Albatrossboss

Hello All,

I have searched and searched the forums and haven't been able to find any info regarding this issue that I call "Phantom Shifting". It is, to me, the best way to describe what is happening.

The History:

The car has around 96,000 miles, as far as I can tell, the transmission has never been serviced based on reading all of the previous owners service records. It does have the 2-3, 3-4 "hoot" problem.

The Issue:

While in 3rd gear in "D" and "Manual" shift mode, the transmission acts as if the car is being shifted from 3rd to 4th at the lowest mph necessary to shift in to the next gear. What I mean by that is if I were shifting as early as possible in to each gear, the transmission would hold 3rd gear from any speed below 22-24 mph before allowing the car to shift in to 4th gear.

The vehicle seems to lose power as if it is releasing the "clutch" to swap gears even though the throttle application is constant throughout all of the gear changes.

This issue occurs at both cold and normal operating temperatures, the throttle application is constant, on straight and level roads, none to light traffic, etc.

The Video:

I have linked the youtube video of the issue here:


The Concern:

My major concern is could it be a bad solenoid? That's the worst case scenario in my mind. I plan on having the transmission serviced and flushed with the Gold fluid and the transmission "flashed" soon. I know that may seem like the logical next step to see if it helps or fixes the issue, but if I just have the fluid flushed once with LifeGuard "Gold" and end up having to drop the pan to replace a solenoid or rebuild/replce the Mechatronic unit, I'd rather kill two birds with one stone.

Any help or past experiences are greatly appreciated.

Mister Bally

In "tiptronic" mode, the shift pattern is extreme and differs on load/torque (up hill vs. down, headwind vs. tailwind etc.

Post a video in "D" mode. One with gentle acceleration and one maybe flooring it or at least entering a limited access highway.

Albatrossboss

Thanks Mister Bally, I will make the videos today. The issue happens in all of those cases, I don't normally drive in Manual mode, I was in Manual Mode to show which gear the car is in when the issue prompts itself.

Albatrossboss

The video below is the vehicle in "D" mode. At the 10-12 second mark is where the "Phantom Shifting" occurs. It is still in 3rd gear and shifts into 4th at the 14-15 second mark in the video.

Granted the engine is cold in the video but believe me when I say that the issue was still present even at normal operating temperature like the last video. This was done in a large flat parking lot in a straight line at gentle/normal throttle.

When more load is applied and the typical shift range is taking place above 2000 RPM, the issue typically doesn't present itself, its typically in the normal/lighter load range of the power band where I do most of my driving.

The video:

mishar

I can't see anything unusual. Could it be that you are mistaken torque converter locking for a "phantom" shifting?

Mister Bally

The video recently posted looks normal to me as well. Maybe try one more aggressively entering a freeway. Even just a gentle entry from low (below 25 MPH) speed to 60-70 MPH.

Are you saying the shift "patterns" you are observing are different than they used to be? If so, a better description please.

MP4.2+6.0

two ideas:

1. Try the adaptation procedure on the TCU/TCM. You need VCDS to trigger it. The procedure and driving adaptation are explained in the latter part of the "hoot" TSB. From doing it myself and being skeptical, right near the end of the whole routine it did make a difference with shift performance and smoothness. it takes about half an hour and you need some very quiet open roads to very gradually speed up and slow down--at least a mile, maybe a few at a time. In my linked prior post below BTW, I've become a skeptic on the whole hoot TSB in general--these cars have way too many miles for it to be reliable as "the" universal fix, it is now obvious to me that the blue fluid isn't magic elixir either since if you read carefully it actually says for the W12 that use the blue as the original fill to change to the gold 4.2 stuff instead, etc. But, the little known adaptation procedure is valuable--from direct experience.

2. From your text description I am wondering some about the solenoids/Mechatronics too. But from having done it personally, in retrospect I think it may have really been the key seal between the Mechatronics assembly and the whole tranny case. See: Separate and Combined Trans Fluid Systems?! - AudiWorld Forums As far as I know, my post and experience is the only one this deep inside the tranny, and there are very few posts about it for Audis generally. It is better understood in the BMW community where the same basic ZF unit was used in RWD form. Just read the post at first to see if some of it rings true, and maybe search my other posts on the tranny topics. If you decide to go after the seal, you can just pull the Mechatronics unit as part of a pan drop and filter change without any further disassembly and the seal is directly above it. If the subject sounds tricky/too difficult, consider taking it to a ZF specialist shop, both for a diagnosis and then perhaps the fluid + filter + maybe seal change out, but not the solenoids. The solenoid kit from a ZF supplier adds about $500 and took me maybe an hour or two to carefully disassemble, clean and reassemble, making one mistake as I went on the park linkage, and praying I didn't break anything among the various plastic bits, particularly where the brain is enclosed in the overall unit. If you just do the gasket, the only cryptic part (besides the inevitable exhaust drop you back into with an S8 or W12) is getting the parking lock part of the linkage reconnected correctly. Neither "the one size fits all" ZF instructions nor the manual stuff are particularly well written or easy to follow. A good number of months and thousands of miles after I did this work I can confirm it is 100% nailed--by chance Mister Bally and his son drove it very shortly after I did it and the morning after I "adapted" it. If anything it is now a bit shift kit like if you drive it more aggressively. This and the upper control arms have gotten me very much back to a new car feeling. In the vernacular (as a W12) it basically kicks butt without even working up a sweat, including at 6000 feet plus where I am just now.

Albatrossboss

All,

Thank you for the replies. I really appreciate the info. I'll try my best to describe this in more detail. The videos seem obvious to me but then again I'm the one feeling the issue at the same time. When the engine is under "normal" load (if I had to put a value on it I'd say 20-30% throttle) the transmission will shift earlier through the gears, typically making the change around 2000 RPM. This can be seen in the videos. The issue is, in 3rd gear, even though I have not let off of the throttle and continued the same 20-30% throttle application, the engine bogs down/loses revs as if I have let off of the throttle, or as if it is preparing to shift in to 4th gear. The transmission then realizes that it is still under load and the revs climb back up before actually shifting into 4th gear.
The engine bogging down happens right around the lowest speed that the transmission will allow the 3-4 shift. So, even in "D" mode the transmission wants to shift at the earliest point due to it's pattern in regards to the throttle position. That's where the "Phantom" shift comes in to play. If you were to count the gear shifts while driving going only on feel, you would think the car has 7 gears. It feels like the engine is shifting to an imaginary gear when it isn't. Hopefully this has cleared up some things for you all.

In regards to Mishars reply, it could be the torque converter locking, but my question with that is, would/could that happen in the other gears while shifting? The vehicle doesn't do this in any of the other gears, only in third.

In regards to Mister Bally, the "patterns" are not different than they used to be as far as I can tell, I've only had the car since the beginning of October and I'm fairly certain that this issue has been present ever since, but was unbeknownst to me because I have had no experience with these vehicles before. Only over time did I start to notice something was amiss in third gear. If this is indeed "normal" behavior for the ZF Transmissions, then I will leave it at that and just adapt my driving style.

In regards to MP4.2+6.0:

1. I plan on purchasing VCDS in the near future, so at the moment I will be unable to perform the adaptation procedure. I do have the adaptation procedure printed out as I have wanted to do this since purchasing the car, kind of like a reset button so I can then start "fresh" and have the transmission learn my driving style. I will go on the VCDS forum and see what help I can gather there and see if anyone near me would lend a hand one weekend.

2. Hopefully I wasn't suggesting that the "hoot" fix was my first choice in finding the real problem, if there even is one. I'm aware of the Mechatronics seal being an issue for you and actually have that thread and some other exterior links to ZF tranny specialists that you linked here bookmarked on my computer. That's kind of why I wanted post this on here to glean any other info I could on it before I decided to either drop the pan and check the seal, or if that would be a waste of time and money if changing the fluid had helped anyone else experiencing this issue.

Once again, thank you all for the help, if this seems long winded I do apologize.

Driver1.8

Looks normal to me also. Under moderate acceleration converter locking occurs in 3rd gear. I've observed this behavior in both the six-speed A8L and the five-speed 99.5 A4 that I owned previously. By observation it looks and feels like an extra gear shift but the transmission actually remains in 3rd gear. Under some conditions the converter will unlock and then lock again in 4, 5, or 6, except in manual mode. In manual mode once the converter locks in 3rd it will remain locked in 4-6.

BTW, on my 2007 the current gear selected by the transmission controller is displayed to the right of PRNDS on the DIS.

MP4.2+6.0

1.Yes, if you don't have VCDS, get your hands on one by borrowing or buying. You want it longer term anyway, and here's an early specific use for it--the tranny adaptation. It could also be you find some codes in the TCU that give you more insight. Those can throw a check engine light--some do, but some don't IIRC from prior experience.

2. This is just a WAG, but consider the MAF. The MAF is tightly coupled to the ECU (obviously) but is also similarly coupled to the TCU as part of the shift decisions. Thus, consider it as well, and maybe at least try cleaning it. On my old C5 era A6 4.2 with the older 5 speed AT, when the MAF was headed south, it did weird stuff to the shifting. It's something you might also feel in the throttle some. Again if you had VCDS you could look for codes here, though with something serious in the MAF a CEL is likely.