How Many Times Does Auto Tranny Shift?
02-13-2007, 10:40 PM
#1
How Many Times Does Auto Tranny Shift?
If i'm correct it should only shift 3 times. The 1st to 2nd shift, 2nd to 3rd shift and finally 3rd to 4th shift. I had my tranny fully rebuilt and for some reason it shifts 4 times!!!! It only happens when i'm cruising or driving in slow traffic the car goes through all 4 gears and while i'm crusing at 2000 in 4th the tranny shifts again and i'm cruising at 1500. If I put slight pressure on the gas it will still accelerate but if I push too hard it will down shift into a higher gear. Anyone know why it does this? Is there any way to check myself to find what gears the car is in?
02-13-2007, 10:46 PM
#2
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Location: New City, NY
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Not sure cuz i drive stick but if i remember back to my sisters trans am, the same thing happened because it was stuck in overdrive. Technically your right, it should only shift 3 times, unless its in o/d, then it would shift 4 times.
02-13-2007, 10:46 PM
#3
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Join Date: Mar 2006
Location: Toledo OH
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Torque Cover locks it's like an extra gear it probably did that before you just didn't notice. The TC locks when u hit a cursing speed between 40 and 50. The TC acts like the clutch in an auto trans. Instead of having to plates that create friction as pressure is applied like a clutch, the TC is basically a hydraulic pump that is driven by the engine. The engine pumps fluid against the transmission causing the transmission to move the car forward. The transmission is free from the engine due to the fluid so it can shift gears and the car can stop with out stopping the engine and the engine can spin about 500rmps - 3000rpms faster then the transmission. Once the auto trans has shifted into 4th the TC's pump locks with the transmission to directly drive the car and the engine speed drops by 500rpms to match the transmission speed. This improves gas mileage and efficiency once you drop below 45mph it unlocks again allowing the transmission to shift again.
02-13-2007, 10:57 PM
#6
www.howstuffworks.com
look up automatic transmission and/or torque convertor.
look up automatic transmission and/or torque convertor.
02-13-2007, 11:01 PM
#7
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Join Date: Mar 2006
Location: Toledo OH
Posts: 170
I edited my original post to be easier to understand
If you notice while your driving about 35 and you are on and off the gas the engine will rev almost as if it's in neutral but if you're on the highway 50mph+ and you do that the rpm's won't move
If you notice while your driving about 35 and you are on and off the gas the engine will rev almost as if it's in neutral but if you're on the highway 50mph+ and you do that the rpm's won't move
02-13-2007, 11:12 PM
#10
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I am not a tranny expert and i have never taken apart a tranny, but i have had another car which had a ****ty tranny, a 97 dodge neon, and i think i know what u r talking about, to get it to switch to another higher gear u need to "force it" by getting on the gas pedal a bit harder, i think your tranny is damaged. sorry to say that, but u should seek a mechanics opinion.
Does it do this only when cold or when the car is hot as well, say after 20 min of driving ?
Does it do this only when cold or when the car is hot as well, say after 20 min of driving ?
02-13-2007, 11:15 PM
#11
it doest it when hot.. but thats just normal auto lag... like i said the old one did the same thing as the new one is so im not real concerned about it... im gonna swap in a 5 speed soon enought and not have to worry about it... all my buddies that have maximas drove it and say its just how laggy these transmissions are..
02-13-2007, 11:46 PM
#13
Originally Posted by LeVeL
Are you sure that it doesnt go into a lower gear? That's what happens when you hit the gas hard. Please elaborate
02-13-2007, 11:49 PM
#14
Originally Posted by Jesse729
Torque Cover locks it's like an extra gear it probably did that before you just didn't notice. The TC locks when u hit a cursing speed between 40 and 50. The TC acts like the clutch in an auto trans. Instead of having to plates that create friction as pressure is applied like a clutch, the TC is basically a hydraulic pump that is driven by the engine. The engine pumps fluid against the transmission causing the transmission to move the car forward. The transmission is free from the engine due to the fluid so it can shift gears and the car can stop with out stopping the engine and the engine can spin about 500rmps - 3000rpms faster then the transmission. Once the auto trans has shifted into 4th the TC's pump locks with the transmission to directly drive the car and the engine speed drops by 500rpms to match the transmission speed. This improves gas mileage and efficiency once you drop below 45mph it unlocks again allowing the transmission to shift again.
02-14-2007, 06:09 AM
#15
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Location: MASS
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Ok, looking at your now edited original post, it is easier to understand it, yes. However I think you could have left out the acceleration part since every automatic will downshift when you hit the gas. Your issue is that while you (think you) are in 4th it manages to shift up. So, obvious stuff first. Are you sure that you're in 4th already when it shifts up? Maybe the revs drop from 2000 to 1500 because you let off the gas? Is it possible to make a video of this? Starting from a standstill and going up to "5th" at constant gas pressure?
02-14-2007, 07:04 AM
#16
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Join Date: Feb 2006
Location: East Granby, Connecticut
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Originally Posted by LeVeL
Ok, looking at your now edited original post, it is easier to understand it, yes. However I think you could have left out the acceleration part since every automatic will downshift when you hit the gas. Your issue is that while you (think you) are in 4th it manages to shift up. So, obvious stuff first. Are you sure that you're in 4th already when it shifts up? Maybe the revs drop from 2000 to 1500 because you let off the gas? Is it possible to make a video of this? Starting from a standstill and going up to "5th" at constant gas pressure?
A different way of looking at it is this...
If you have an automatic transmission, your engine is never really engaged to the transmission until 4th gear. Rather, it's throwing fluid at it to get it spinning (think of a water wheel). The transmission will up shift to second, then to third, then to fourth. (shifting refers to the gears... if you are going from a higher gear to a lower gear, i.e. 4th to 3rd, you are downshifting, which results in more power, RPMS, and speed). Once you are in fourth, the tossing of fluid is no long necessary, and the engine gear can connect directly with the transmission. Obviously the engine was working hard to get the transmission going with fluid, so when it connects to the transmission, it is moving faster than the transmission is, and the two connected will obviously move at the same speed. The components of the engine are obviously a lot smaller and have less mass than the entire car, which is what the transmission is representing (the speed the tires are spinning), so this connection is going to slow the engine down rather than speed the transmission up. This is why the engine slows (drops RPMS) as it does when it shifts. When you hit the gas to get going faster, the engine wants to move faster, but now has the transmission bogging it down. So it abandons that connection because hurling fluid is easier than pushing gears, so the engine revs up and it feels like a downshift, even though the tranny has been on it's fourth gear the whole time.
Yes, I do realize I repeated a lot of what Jesse729 said, but some expressed confusion by his explanation, so I wanted to elaborate for those that are confused.
02-14-2007, 09:05 PM
#17
That was a good explanation. Does anybody elses tranny shift too soon sometimes when going from first to second? Say you are behind someone turning right and you're going straight. You first accelerate slow because the other car is in front of you, then when you have a free strech of road you give in more gas. However the second you give in more gas the tranny shifts. Has that happened to anyone before?
02-14-2007, 10:45 PM
#18
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Join Date: Feb 2007
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Originally Posted by 97MaximaSE97
That was a good explanation. Does anybody elses tranny shift too soon sometimes when going from first to second? Say you are behind someone turning right and you're going straight. You first accelerate slow because the other car is in front of you, then when you have a free strech of road you give in more gas. However the second you give in more gas the tranny shifts. Has that happened to anyone before?
And to answer your question... yes, the auto pisses me off when i am about to step on the gas and it is just changing gears and then has a giant lag and/or lurch.
02-15-2007, 04:52 AM
#19
Originally Posted by 97MaximaSE97
That was a good explanation. Does anybody elses tranny shift too soon sometimes when going from first to second? Say you are behind someone turning right and you're going straight. You first accelerate slow because the other car is in front of you, then when you have a free strech of road you give in more gas. However the second you give in more gas the tranny shifts. Has that happened to anyone before?
Electronically-controlled auto trannys like ours are supposed to shift by the ecu when torque drops off in any particular gear. It shifts fine, just early. I have a 98 SE with 118,000 miles, maintained properly, mostly stock, just a budget y-pipe.
02-16-2007, 09:26 AM
#21
Before I bought my 5spd I had an auto. I felt at times that my max was laggy at times, mostly once it was warm. Believe it or not I solved the problem with a simple tune up and I had my Coolant system completely flushed and vaccuumed, having the block flushed of coolant is what really made the difference. Even though my ride never over heated, flushing the coolant made a big difference in engine response. However I just bought my 5spd SE I learned how to drive stick in it, and now I love it.
02-16-2007, 03:33 PM
#22
Originally Posted by 97MaximaSE97
That was a good explanation. Does anybody elses tranny shift too soon sometimes when going from first to second? Say you are behind someone turning right and you're going straight. You first accelerate slow because the other car is in front of you, then when you have a free strech of road you give in more gas. However the second you give in more gas the tranny shifts. Has that happened to anyone before?
BTW, these Nissan trannies are designed to shift when you give it anything but the slowest and lightest possible pressure on the gas pedal...especially at speeds 30 and over. It is really hard to cruise at 30 unless you have a light foot.
Now, my tranny has the opposite problem as well..that is, it will not downshift into 1st when I stop at a stop sign UNLESS I really come to a complete stop and sit there for two seconds. If I don't either it will stay in 2nd gear (weith me hopelessly punching the gas), or it will kick into 1st with an accompanying kick in the back.
4th Gen trannies were never a bright spot.
02-16-2007, 03:47 PM
#23
^If the car drops into 1st it would be much rougher and jolty, which is awesome for the enthusiast but the Max is more of a luxury model than a sports car, gear toward smoothness moreso than brisk snappy shifting.
Unless you have a 5spd ha, oh how sweet it is.
Unless you have a 5spd ha, oh how sweet it is.
02-16-2007, 03:55 PM
#24
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Join Date: Dec 2002
Posts: 67
As one mentioned in the above post, the tranny shifts are controlled by the ECU. And the ECU learns how you drive. If you have a heavy foot, it will be more agressive and "lazier" to shift (most likely it will always shift close to red line). If you have a light foot, it will always shift early to get better fuel economy.
Either way, I found a "way" to reset the ECU learning.... you could try and see whether you notice any difference.
Put your key into 2nd position (the position right before you turn on the engine).
Floor (press all the way in) the gas pedal for 5 seconds
Turn your key back to 1st position
Let go the gas pedal
Wait for 2 minutes (some people say it's optional)
Start the engine, drive the car and see the difference.
Once again, if you have a heavy foot, don't expect much of a difference. If you have a light foot, you should notice some difference how and when the tranny shifts. It should allow you to do more agressive driving.
Good luck!
Either way, I found a "way" to reset the ECU learning.... you could try and see whether you notice any difference.
Put your key into 2nd position (the position right before you turn on the engine).
Floor (press all the way in) the gas pedal for 5 seconds
Turn your key back to 1st position
Let go the gas pedal
Wait for 2 minutes (some people say it's optional)
Start the engine, drive the car and see the difference.
Once again, if you have a heavy foot, don't expect much of a difference. If you have a light foot, you should notice some difference how and when the tranny shifts. It should allow you to do more agressive driving.
Good luck!
02-16-2007, 04:03 PM
#25
Originally Posted by zoink
As one mentioned in the above post, the tranny shifts are controlled by the ECU. And the ECU learns how you drive. If you have a heavy foot, it will be more agressive and "lazier" to shift (most likely it will always shift close to red line). If you have a light foot, it will always shift early to get better fuel economy.
Either way, I found a "way" to reset the ECU learning.... you could try and see whether you notice any difference.
Put your key into 2nd position (the position right before you turn on the engine).
Floor (press all the way in) the gas pedal for 5 seconds
Turn your key back to 1st position
Let go the gas pedal
Wait for 2 minutes (some people say it's optional)
Start the engine, drive the car and see the difference.
Once again, if you have a heavy foot, don't expect much of a difference. If you have a light foot, you should notice some difference how and when the tranny shifts. It should allow you to do more agressive driving.
Good luck!
Either way, I found a "way" to reset the ECU learning.... you could try and see whether you notice any difference.
Put your key into 2nd position (the position right before you turn on the engine).
Floor (press all the way in) the gas pedal for 5 seconds
Turn your key back to 1st position
Let go the gas pedal
Wait for 2 minutes (some people say it's optional)
Start the engine, drive the car and see the difference.
Once again, if you have a heavy foot, don't expect much of a difference. If you have a light foot, you should notice some difference how and when the tranny shifts. It should allow you to do more agressive driving.
Good luck!
02-16-2007, 04:20 PM
#27
Senior Member
Join Date: Nov 2006
Posts: 2,391
hey hey hey wait a minute here waiiit just ONE minute...
There is no mention of this in the manual, i WOULD assume something like tranny memory mapping would be mentioned. The manual mentions that we have hydraulically adjustable break pedals which you adjust in a similar fashion, but more on that in another thread...
Can anyone confirm this Tranny memory statement and method of accomplishing it ?
There is no mention of this in the manual, i WOULD assume something like tranny memory mapping would be mentioned. The manual mentions that we have hydraulically adjustable break pedals which you adjust in a similar fashion, but more on that in another thread...
Can anyone confirm this Tranny memory statement and method of accomplishing it ?
02-16-2007, 06:26 PM
#28
Member
Join Date: Dec 2002
Posts: 67
I don't think it will ever be mentioned in the manual. It's something that 90%+ car owners out there don't understand, don't need to understand or don't care.
I've been doing this at least once a month (sometimes 2-3 times a month) for almost a year (my wife is a granny driver
). I feel it faster. Even if it's indeed not (just psychologically), it does not do any harm to any parts, including the ECU.
I've been doing this at least once a month (sometimes 2-3 times a month) for almost a year (my wife is a granny driver
). I feel it faster. Even if it's indeed not (just psychologically), it does not do any harm to any parts, including the ECU.
02-16-2007, 07:24 PM
#29
Originally Posted by dr-rjp
You may have a faulty TPS (throttle position sensor) which is sending premature signals to the TCU (transmission Control Unit).
BTW, these Nissan trannies are designed to shift when you give it anything but the slowest and lightest possible pressure on the gas pedal...especially at speeds 30 and over. It is really hard to cruise at 30 unless you have a light foot.
Now, my tranny has the opposite problem as well..that is, it will not downshift into 1st when I stop at a stop sign UNLESS I really come to a complete stop and sit there for two seconds. If I don't either it will stay in 2nd gear (weith me hopelessly punching the gas), or it will kick into 1st with an accompanying kick in the back.
4th Gen trannies were never a bright spot.
BTW, these Nissan trannies are designed to shift when you give it anything but the slowest and lightest possible pressure on the gas pedal...especially at speeds 30 and over. It is really hard to cruise at 30 unless you have a light foot.
Now, my tranny has the opposite problem as well..that is, it will not downshift into 1st when I stop at a stop sign UNLESS I really come to a complete stop and sit there for two seconds. If I don't either it will stay in 2nd gear (weith me hopelessly punching the gas), or it will kick into 1st with an accompanying kick in the back.
4th Gen trannies were never a bright spot.
02-16-2007, 09:37 PM
#30
Originally Posted by TunerMaxima3000
^If the car drops into 1st it would be much rougher and jolty, which is awesome for the enthusiast but the Max is more of a luxury model than a sports car, gear toward smoothness moreso than brisk snappy shifting.
Unless you have a 5spd ha, oh how sweet it is.
Unless you have a 5spd ha, oh how sweet it is.
02-17-2007, 06:12 AM
#31
Don't know if this has already been mentioned, but there is "4th slip" and "4th lockup". The same gear but the torque converter makes it feel like it's two different gears so in certain situations it will feel like 4 shifts.
02-17-2007, 08:48 AM
#32
Originally Posted by zoink
As one mentioned in the above post, the tranny shifts are controlled by the ECU. And the ECU learns how you drive. If you have a heavy foot, it will be more agressive and "lazier" to shift (most likely it will always shift close to red line). If you have a light foot, it will always shift early to get better fuel economy.
Either way, I found a "way" to reset the ECU learning.... you could try and see whether you notice any difference.
Put your key into 2nd position (the position right before you turn on the engine).
Floor (press all the way in) the gas pedal for 5 seconds
Turn your key back to 1st position
Let go the gas pedal
Wait for 2 minutes (some people say it's optional)
Start the engine, drive the car and see the difference.
Either way, I found a "way" to reset the ECU learning.... you could try and see whether you notice any difference.
Put your key into 2nd position (the position right before you turn on the engine).
Floor (press all the way in) the gas pedal for 5 seconds
Turn your key back to 1st position
Let go the gas pedal
Wait for 2 minutes (some people say it's optional)
Start the engine, drive the car and see the difference.
02-17-2007, 10:43 AM
#33
Member
Join Date: Dec 2002
Posts: 67
From someone in benz forum.
Well, it could be just my psych. But I feel it works for all my benzos (plus bunch of people over there)... and I feel it works for max also (now I'm trying to see whether some people also feel the same way).
For my benzos, at least I could have more visible measurement beside my butt The ESP light turns on a lot more often than before the "reset", especially from a dig.... 
Well, it could be just my psych. But I feel it works for all my benzos (plus bunch of people over there)... and I feel it works for max also (now I'm trying to see whether some people also feel the same way).
For my benzos, at least I could have more visible measurement beside my butt
The ESP light turns on a lot more often than before the "reset", especially from a dig....
02-17-2007, 12:22 PM
#35
There is really no way to test the "reset" idea. You can don a few 0-60 runs and then do the "reset" and some more 0-60 and compare the averages but my guess is that it's a waste of time. IIRC the max was designed to learn behavior right? After you drive a certain way for a while the car adapts itself that way. Idk if that's on all cars or just the max, not something I've ever looked into. But I've never heard of it being able to reset itself by pushing in the gas pedal. Someone test it out.
02-17-2007, 12:38 PM
#36
Originally Posted by Cdg2125
IIRC the max was designed to learn behavior right? After you drive a certain way for a while the car adapts itself that way.
02-17-2007, 01:01 PM
#38
I'm not sure where I got that from. I think I read it in a thread in all motor some time ago. I have no idea now. Glad you called me out on it tho. Maybe I was thinking A33...idk. Sorry about the mis-info.
02-17-2007, 01:06 PM
#39
I can't find where it states that in either FSM. The only difference is the CAN lines for the A33B.
I noticed it one time I was late for work. I was doing some extremely sprited driving, and noticed that I couldn't even look at the throttle the wrong way and it would DS.
I noticed it one time I was late for work. I was doing some extremely sprited driving, and noticed that I couldn't even look at the throttle the wrong way and it would DS.