in2audi

I read your post about having a solution for the 3 to 4 shift flare. My Audi also has problems shifting into and out of the 3 to 4 position (the RMP's will rev up prior to shifting). I've had this problem now for several years and have not been able to find a solution. After seeking the advise of several Audi mechanics, transmission pros, and many AW posts I had finally come to the conclusion that the only solution was to replace the failing unit. So I recently put in a transmission I found with only 76k. All in all the new trans shifts much smoother, although I was very disappointed to find the 3 to 4 problem still persists. On the advise of my mechanic I replaced the kick-down switch ($65), but still the problem persists. So far I've spent over 1k trying to solve this, I'm at my wits end!!! Any help would be greatly appreciated.

seattle 93q avant

Here is the description for locating the broken washer:

On the drivers side of the transmission next to the CV half shaft there
is a
circular indentation in the transmission case about 2" across. The
circle is
a cover or plug in the side of the transmission. There is a bullseye
type
design cast into the cover with several numbers on it. Also the
transmission
cooler lines run right in front of this cover.

I had to remove the front exhaust section and the two transmission
cooler lines
to gain room to work. The cover is held in place by a single C-Clip.
Once you
remove the clip, the cover may pop out or you may need to tap on it
lightly to
get the cover to come out. There is light spring pressure behind the
cover.

Once the cover is off some transmission fluid will drain out of the
hole, be
ready. With the cover removed there is a metal disk attached to a rod,
pull
the
tip of the rod and remove the entire assembly. There will be the disk,
rod,
and 2 springs. There are also 2 washers on this rod, one of which may
be
broken.

Be sure you get all the pieces of the broken washer out of the hole.
The part
you have just removed and will replace is called the "C" Band Servo
Piston, I
replaced the whole assembly. I had a tough time locating anyone who
knew what
I was talking about at the transmission shops linked from the ZF web
site. I
ended up buying the parts from a man in Canada. He really knows his
stuff and
had the part in stock. I received it next day Fed Ex. It ended up
costing
about $60.00 U.S. but it was worth it, the shipping cost was more than
the part.

As you look more into this I can give you more details. I am concerned
that
this may not be your problem, as your symptoms are not the same as
mine.

My car when shifting from 3rd to 4th would free wheel or act as if it
were in
neutral for a split second before engaging 4th gear.

HenryK

this has been a solution in the making for some time. I suspect that many on this board are experiencing similar problems with their 3rd to 4th shift. Some may not even know they have a problem. However, are you sure it revs prior to shifting or do you mean during the 3rd to 4th shift?

I am awaiting parts to complete my repair. Sam of course has successfuly done it and is the first to my knowledge to address it successfully.

in2audi

The strange thing is that with my old trans it started with the shift flair from 3 to 4 and developed (over several months) into a shift flair both into and out of 4th (RPM's jump prior to both up and downshifts).

Now my new trans only does it on the downshift from 4 to 3. The EXACT same shift flair but ONLY on the downshift.

Anyone experiance this problem on downshift? I'm guessing if this "C" band servo piston is responsible for the shift into 4th that it also has something to do with the shift out of 4th??? My guess?

HenryK

I think we are talking about the same thing, but using different words. The only way it can flare is when the transmission has released third gear and awaits fourth. The rise in engine rpm's happens at this point between actual shifts. If the rpm's are rising while in third gear the transmission is slipping which is another story. However, I suspect you do indeed have a faulty servo piston. If the parts, such as the washer's Samm has indicated in his post, are not broken then the springs on the piston have no doubt become fatigued over time (you may even have both conditions), resulting in the servo/piston not function properly. I am not sure that this servo/piston is even normally replaced during a typical tranny rebuild.

in2audi

Do you know if this faulty servo piston or springs could affect downshifts as well as upshifts?

HenryK

I have the flare to be usssulally evidewnt during light throttle conditions. The parts are not that expensive especially compared to what you have forked out already....it maybe worth a shot.