I took it to dlr and asked them to flush as suggested here- they said it wouldn't help because whatever shavings were left were holding things together (and they didn't have pump). FLUID CHANGE DIDN"T WORK. I asked them to save old fluid and they didn't, saying "it would take two mechanics". I took it in last December for improper shifting and they did not do a thing except note "trans searching for gear" on bill. question 1)should/could they have done anything else that might have saved it? 2)I'm going to drive it until car doesn't move, what can I expect? Sorry for the length and thanks for feedback! Friend wants to sell ex. condition a4 wagon w/ 120k for 8,400-any common prob's?

 

I dont want to drive a car with a broken tranny.. however i do not want to repace a tranny that works..

Heres my dilemma. I know that this bastard of a transmission will never fail. It hunts and shudders, but because i want to replace it when it dies it will never go. Its been 1 year and its still holding on. I have a fealing it wount get any worse.

I will be danmed if i ever let audi touch my transmission ever again. If i were you i would double check your fluid. I wonder if they even did it.

 

When people get the "limp home" mode....they usually get "incorrect gear ratio" which essentially means that the clutch is slipping.

There is a speed sensor on both sides of the clutch and if it sees too much difference in speed, it says incorrect gear ratio and puts it into limp home mode.

I've heard of at least two or three cases personally that after that happens, changing the fluid and filter has helped significantly.

Never has it caused the transmission to degrade further.

In these cases, it worked for a while, then required another flush. Sometimes another one, but then it worked again.

I think having all the little things in the tranny is worse than having clean fluid. I believe the foreign material in the fluid causes a lower coefficent of friction between clutch plates as compared to having clean fluid and the entire clutch plates sandwich against each other. I think the foreign material decreases surface area or has a lower coefficent of friction.

After Randy's talk about his Range Rover again, I'm really thinking about trying synthetic in my gear box in the spring before my first track event.

 

It aint perfect, but one filter and fluid change at $400 and a follow up flush at $150 sure as a heck beats the alternative. It's been a year for me as well and it's temperamental but it does not go into limp mode anymore and I love my car again. Our relationship was strained for awhile. I was looking at E430s and 740s, now I am looking at an 01 or 02 A8. Think I will be able to get $7 or $8k for a 110k mile A8 with a temperamental but working transmission? If I have to dump it for $6k, I may get pissed enough to get a Q45 and I have never been a fan of Japanese.

 

This may be a stupid question, but could replacing the clutch help?

 

Did PaulW just volunteer to be the tranny guine pig?

 

That's called a rebuilt tranny.... :-)

 

Here is a picture of TozoA8's clutch pack....this is clutch A and clutch B (sounds kinda like Dr. Suess, doesn't it?).....

The oil pump is a gear pump, the stationary part can been seen in the upper right of the picture.

<img src="http://pictureposter.audiworld.com/80919/dscn1351.jpg">

There are basically two motorcycle wet clutches on the shafts and the hydraulic valves controlled by solenoids activate the hydraulic pressure to them to activate or deactivate them.

There is a input shaft and output shaft....speed sensors on each one or a signal that is proportional to it.

One of the clutch housings is steel, while the other is aluminum so it only picks up the speed sensor on the steel one....has a toothed gear or something.....

When these things start slipping, you get the inccorect gear ratio and it pops it into limp home mode.

TozoA8's tranny wouldn't even get the car going, sometimes with no gas in drive it would start rolling, but as soon as the gas is given, it would slip and go into limp home mode.

His Clutch A was toast.

We are getting closer to understanding the mysteries of these trannies!

 

From a few paragraphs down:

"AMSOIL Synthetic Oils will prevent deposit buildup on clutch plates, therefore keeping the face clean and able to do its job in preventing slippage."

That's what I'm talking about....dirty fluid is not going to perform as good as clean fluid

------------start write up---------

AMSOIL Synthetic Oils: Slipperiness and Wet Clutches

Many people have the perception that since synthetics are more slippery than petroleum oils (which simple don't reduce friction as well), that wet clutch packs in either their automotive automatic transmission or motorcycle transmission will slip when using "super slippery synthetics". AMSOIL Synthetic Oils are no more "slippery" than petroleum oil. AMSOIL Synthetic Oils simply have a more uniform molecular structure which reduces frictional resistance better than the irregular shape and size molecular structure of a petroleum oil.

Look at it this way. Wet sandpaper removes paint as well as dry sandpaper does. The slipperiness of the water does not impede the sandpaper's ability to function. The same applies to the "slipperiness" of synthetic lubes in wet clutches.

If used dry, the sandpaper is soon filled with paint and no longer works- it slips across the surface without grasping the surface. If kept clean and free of paint, it continues to work. The lubricating/cleaning solution used can be water, soap, oil or any other liquid. The liquid's slipperiness does not affect the performance of the sandpaper.

It is simply not an issue. However, just as rinsing the sandpaper keeps it cleaner longer so it functions better longer, so the AMSOIL Synthetic Oils keeps wet clutch plates cleaner longer so they function better.

AMSOIL Synthetic Oils will prevent deposit buildup on clutch plates, therefore keeping the face clean and able to do its job in preventing slippage.

And, since synthetics are superior cooling agents to conventional petroleum lubes, using synthetics will help wet clutches last longer, too.

Petroleum oils have low resistance to heat and allow varnish and glaze to form on clutch plates, which eventually leads to slippage and increased heat generation and eventually failure of the clutch pack.

Also, AMSOIL motorcycle oils are specifically formulated without any friction modifiers for compatibility with wet clutch packs. AMSOIL ATF lubricants are also designed with specific coefficient of friction values to meet the requirements of each and every specification that it not only meets, but far exceeds.

Now you know the facts. The next time your buddy mentions using AMSOIL Synthetic Oils and Wet Clutches as a potential issue, you can explain to him exactly why it is simply not an issue.

 

<img src="http://www.dansmc.com/honxr600r_clutch.jpg">

This is a motorcycle clutch from a honda I believe....but same concept.

There are clutch discs (9) and friction plates (8). The discs are smooth, the friction plates are clutch material.

You can see that the discs (9), attach to number 13, the clutch center.

The friction plates (8), attach to 15, the clutch outer housing.

One is the input shaft, the other is the output shaft. There are springs that sandwich the whole thing together (3) by pressing on the pressure plate (4) and allow the plates and discs to transfer power between them.

When you pull on the clutch lever, it releases the spring pressure and the input/output shaft can spin relative to each other (engine still running, but motorcycle standing still)....let the clutch lever out, they slowly hook up (motorcycle moves forward).

The solenoid valves in the tranny provide this same function with hydraulic pressure.

When the input shaft is spinning, and the output shaft is not (as seen by the computer), it knows there is slipage and says "incorrect gear ratio" and puts the tranny into limp home mode.

This concludes our training on ZF transmissions for today......