I was driving pretty aggressively yesterday and I got the car around 5.5k rpm in 2nd and decided to upshift. I heard this loud thunk and the car shifted very harshly and the rear got a little squirrely. Has anyone noticed that if you have the pedal floored and short shift, the tranny shifts very harshly compared to just flooring it in auto mode?

 

i have noticed that also but dont know what it is

 

I haven't noticed this, but I have a question of my own kinda on topic. Is there any danger to my engine or Transmission when driving in MM allot? I drive in that mode almost all the time and always downshifting as if I was drivng a MT. Again so I was wondering is there any danger or harm in driving in this mode allot (downshifting, upshifting etc) Thanks

 

Danger in MM: .. hmmm ... if you drive agressively .. for instance ... shift at about 5.5K RPM Regularly ... tehre is going to be more wear and tear .. you guys know the general rule. thats it .. if you drive regularly in MM .. then just be careful not to constanly rev your engine very high. I have experienced the Lound THUNK as well .... i dont know what it is it ...

 

This is very good topic, cuz I am interested in that as well. I tend to avoid using the manual shift if possible, becaus the auto does do a sufficent job with shifting.

I heard that usually around the 4000-4700 RPM range is the best time to shift, true?

 

From everything that I've read, running the car in MM mode even ALL the time is just fine for the transmission. Shifting back and forth as often as you'd like is also OK on the car. I shift back and forth all the time when cruising on the highway, starting it up at a light or even when im around town at 35 mph and really want people to hear my exhaust notes!

 

Yeah but it'll probably put more wear and tear on the tranny due to higher strain on the tranny. Full auto mode is definitely more smooth than the manual mode because the computer can fully compensate and anticipate for shifts. In manual mode, if the computer is thinking rev and you suddenly upshift/downshift, it'll "bang" it into gear and that certainly isn't good for the tranny. I'm just wondering if I'm the only one that confuses my tranny in manual mode.

 

I've also had the confused MM.. the bang is a neutral drop (of sorts, more from tranny lash) Basically, it lags long enough to drop pretty hard on the next gear. I've had it happen after driving in a 'spirited fashion'. Luckily our ATs seem really tough. I plan to do a 30K flush, but I'm not worried about the tranny in general.

 

The bang comes from short shifting. You need to let it wind out just a little longer or if you are going to short shift, you need to lift the throttle to avoid the bang.

Our trannys are also used in the Q45 so they are extremely tough. MM mode is fine as often as you'd like to use it if used properly.

 

actually, I find lifting the throttle induces the bang in some situations. I suppose you've build up all that pressure, but sent a different message to the TCU which leisurely shifts.

 

I've felt it shift harder than in full auto mode, but only when I'm really on the gas. To me it just felt like a harder shift - not a clunk or anything irregular. My diesel truck does the same thing when I have my "foot in it." It grabs second so hard it'll bounce your head off the headrest.

I disagree that driving in manual mode causes 'extra wear and tear' or 'strain' on the transmission. I believe that unless you're really abusing the tranny - hard engine braking for example - that it will be fine. if it wasn't meant to be downshifted, why did they build it to rev-match for just that reason? The manual even addresses how to use the tranny for engine braking. There are no warnings, no cautions, or limitations that wouldn't be seen as common sense - like not trying to downshift into 1st @ 60MPH or something.

KAHBOOM makes a good point. This tranny is being used in a car with more power, more torque, and more weight than ours. The recommendations in the Q match the recommendations in our manual, without exception.

 

when you shifted were you turning at all? if so, thats gonna happen. if not, don't know.

I shift quite often & hard no prob's yet!!

 

Dude, what's with your G wearing blue eyeliner? That's so 80's.



In my case, I was winding the hell out of her on a straight-away. I felt the hard shift going 2-3. It wasn't anything I worried about - if you ever sat in my truck while it was shifting under a load, you wouldn't either.

 

ha!.....road racing at VIR a couple months back.

I did a "1/2-a$$ed job" because it was a 2 day event & I had to drive to the hotel that night & didnt bring enough tape

 

So, I've heard a couple of different points of view that does kinda worry me. I mean if it could possible put more wear and tear on the Tranny that can't be a good thing. How about this when in MM when do you guys **** your car or moderate and aggressive driving? Second one of my main concerns was when I downshifted for braking. How do I know when it's too much to do so. For example if I'm in 3 and down **** to 2 for a turn and my Rpm's are above WHAT is too much 3,000, 4,000, 5,000 what is too much so I can learn what my car does when downshifting and where I should be when doing so? Thanks very much guys you guys have helped me out allot.