View Full Version : transmission problem


Marv K
10-27-1998, 04:27 PM
I have a new A4 2.8 Quattro with 2000 miles on it.<br>It has the tiptronic transmission. I have noticed on two recent occassions that when I start driving th car after it has been parked for several hours that the transmission when set in D4 will not shift up from first when it should for a short distance. I would like to know if others have experienced this or is this a transmission problem.<p>Thanks

Cameron
10-27-1998, 04:43 PM
The "D4" gear (4th select gear) is designed to 'shift' the transmission logic. As opposed to other cars where the transmission follows the same shift maps in any "D" setting, but is limited, the ZF transmission in the A4 figures out that you want it to limit itself at the >40mph range reach of the shift map. In fact, many people asking for more performance at the better dealers (Motorwerks in Chicago and Barrier in Seattle are the two dealers that have given me this advice for a 2.8A4Q) get the answer, "Leave your gear selector in the fourth select gear unless you're on the highway, it will rev higher in first and second and exercise more of the torque map." Sounds crazy, right? I called AoA earlier this year, and there are actually different maps for each transmission setting. I used this documentation on shift logic and remapping for my transmission work earlier this year, but you can email me for specifics on map layout (apparent layout and projected layout) and transmission setup. Under medium to hard throttle, if your transmission is acting properly in D4, it should upshift 1500 to 500 rpm before redline depending on throttle position and other factors.<p>And in response to a recently received email...<p>Note: I do not suggest that A4 owners modify their transmissions, make any changes, attempt to decrease shift time, or machine new gates, bearings or fittings for their transmissions. Further, this message contains no implication that electronic changes in the transmission, programming changes, or other modifications are either prudent or covered by warranty. Modification of transmissions in modern touring cars is not an exact science and is prone to mistake and damage -- I am not responsible for any damage to persons or property as a result of transmission modifications made because of the advice authored on this bulletin board.<p>Cameron

Kirk
10-27-1998, 05:47 PM
Cameron,<p>Are you saying that the Tip, if in the Auto mode, not Manual Tip mode, should be left in 4th for around town driving and not put in 3rd? Or am I misunderstanding what you are saying. It would seem to me that if you want more power, you should maintain it in the D3 position around town, that way it will hold in 1st and 2nd longer and ultimately hold in 3rd. But, I would be worried about excess wear on the tranny, too.<p>Now, this could be easily complicated my computer shift mapping programs, but I am looking for a relatively simple answer. I do not want to damage my soon to arrive A4 2.8Qtip (anyday now, come on customs, MOOOOOVE IT). But, I would like some more spirited driving around town sometimes and when I testdrove the A4 2.8QTip, it seemed to be more responsive in the D3 position. What do you think?<p>Kirk

Cameron
10-27-1998, 06:29 PM
My car defaults to manual mode, because of the gate design, and I shift it manually 99% of the time. It does not automatically downshift and it does not have a rev limiter, unlike the transmission you will have on your car. Also the shift time is significantly faster, and the matching of rpm's between gears more important.<p>When I drive the 2.8QTip, I usually shift in the main auto gate. Three, Four, and Drive are the settings I use with that gear selector. Sometimes I'll use second in auto mode on an icy morning drive. I generally prefer manual transmissions, and I'd rather the computer have intelligent input from the shift selector than have no intelligent input at all. Remember that the computer, as smart as it is, cannot see the road, nor the minivan swerving in front of you, nor the strange conditions ahead, nor listen to the weather forcast on the radio. Hence, when possible you can narrow the choices available by using the gear selector, narrowing the chance that your transmission will make a patently wrong gear choice. As with a manual transmission, however, sometimes the input from the driver is more faulty than helpful -- make no mistake about it, I'm guilty of flawed input with automatics, Tiptronic, manuals, etc. However, when in doubt, I leave it in "D", shifting into neutral at stoplights, and using the handbrake properly when the rear wheels need locking during stopped or near-stopped situations. There is surprisingly little difference between the Tip and Manual versions of the A4 which, in my opinion, is a blessing not to be overlooked.<p>Cameron

Kirk
10-27-1998, 10:19 PM
Do you think it is satisfactory to (if you are only using Auto mode in Tip) leave it in D3 in the city (what little city I now live in ;) ) or will that cause too much strain on the tranny over time. Also, I inferred by your post, that D4 actually had a more favourable gearing ratio/torque utilisation than D3 in city driving. Was I reading this incorrectly?<p>Thanks,<p>Kirk

Cameron
10-27-1998, 10:38 PM
... so long as the driver (you) doesn't do anything phenomenally off-the-scale stupid, it won't hurt anything. The standard ZF unit has very conservative maps compared to the floorboard Porsche 996 mapping, so I wouldn't worry. My comments were more pointed toward smoothness and driver enjoyment than safety, as routine use of the settings in a reasonable manner will not hurt anything.<p>Cameron<br>

Kirk
10-27-1998, 11:54 PM
I think what I will try then is to use D3, when not in Tip mode, in city and then go to D4 as I join the expressway (or rural cowroads here, THAT's a highway?, it practically has stop signs the people drive so slow!).<p>Thanks for the advice,<p>Kirk