Tiptronic Question

[cjoenck]

I need confirmation that the following behaviour is normal or cause for concern:

Car is a '91 C2 with approx 70K miles. I bought the car in the spring with an incomplete maintenance history and have had a few small surprises.

When accelerating in semi-manual mode in 2nd gear at around 2,000 rmp I get a dip in acceleration, almost like there is another gear shift. RPM fall back approx. 200 and then move smoothly back up and on. I then accelerate smoothly beyond 3,000 rpm before shifting into 3rd and ultimately 4th. This behaviour only shows up in 2nd gear. The same behaviour is noticeble in fully automatic mode but not to the same extend.

How worried should I be?

Thanks for any insights.

OK, decided to try an ATF change and strainer clean first. Has anyone out there a link to procedure or some do or don't recommendations? Thanks

[simon.marsh@xtr]

Hi, your problem could almost be the same as mine. See my recent post "964 C2 1992 Tiptronic Vibration under power " my cars done around 80Km and when I take off in 1st or second gear I find the same effect. Its almost like a clutch is not completely locking in then it does, hence the "extra gear" feel.
I wish someone could suggest whats wrong

[cjoenck]

I did a little more research - apologize if this seems like a no-brainer but I am still somewhat new to the 964 - and the Tipronic ATF should be changed ever 24K miles / 40K km. I have no idea when this was last done on my car but it's a realitively inexpensive task, approx $100 in parts and fluid if you include a new strainer. So I'll do that and see what happens.

Any other suggestions are highly welcome.

Thanks

[dick911]

Mine does the same and all the other Tips from the 964 range I drove, show this 'behaviour' ... So in mine opinion it is normal

Anyone else ?

Dick911

[gizmofixer]

My Tip does the same thing, as did every other 964 Tip i've driven.
BTW----Dont expect any different response after changing the trans fluid,
i was determined to 'cure' this and tried everything from fluid to mounts, until i drove a number of others and learned it is indeed normal.
Drive and enjoy!

[simon.marsh@xtr]

My previous '91 964 didnt do this at all thats why I reckon its a fault with my current car. I do get vibration under power too. it could be a totally different problem (engine mounts etc)

[BReyes]

There should be no vibration though.

[Pete000]

What you are feeling is the torque converter lock up. This is normal. They all do it.

[geolab]

There are two issues here.
1st: this is no second gear at 2200rpm in 2nd. This is the torque converter on purpose that smoothens the shift between first and second gear. If this did not exist, it would be like popping off the
clutch in a manual gearbox everytime you shift from first to second.
This is oil pressure/tiptronic mapping controlled, and it feels like an extra gear between 1 & 2.
When you get familiar with it, you will notice that it does not exist (happen) while decelerating.
Take care to change the ATF and tiptronic gearbox filter every 20000kms. The gearbox will stay agile.
Change the differential oil as well. You will see a difference, because people tend to forget to change those.
2nd: tiptronic gearbox has five computer mappings. Two of which are sport. These are controlled by the way you drive.
To make sure the Sport mapping is used, push the accelerator pedal to the floor (while driving), release
it and push it back very swiftly to the floor (max).
Do this twice in a 30 second interval (max.3 minutes)
take care while doing this.
you do not have to do this in first gear or second, any gear will do

________________________________

993 Carrera S '97

[cjoenck]

Thank you so much for the information and background! I did change the ATF fluid and noticed much smoother shifting. Very nice. Thanks to all your feedback I am actually beginning to understand the inner workings of the Tiptronic. What an incredible piece of engineering, considering the time it was invented.

[BReyes]

Been taking it easy. The other day I was entering the highway and on the on ramp WOT in drive. It did not do what I wanted it to and rattled (best word I can think of right now) but I kept it to the floor for a couple of seconds.

I will always( ok just mostly) put in manual, downshift carefully and WOT from now on- oh yeah so smooth.

[96740]

Originally Posted by Pete000

What you are feeling is the torque converter lock up. This is normal. They all do it.

+1

[12own911]

Hi Guys. Do you know if anyoe installed a 964 with Tip in an early car like a 72? I was thinking this could be done but wanted to check? Please let me know.