Chevrolet Malibu Forums banner

Status
Not open for further replies.
1 - 15 of 15 Posts

·
Premium Member
Joined
·
714 Posts
Discussion Starter #1
Hi All

It is not a problem or anything, just my curiosity.

In the city I can give the some moderate amount of gas and the 6sp kicks down a gear quite willingly and nicely. On the highway, however, it's different. I can't yet figure it out entirely. Seems like half of pedal travel will keep in 6th and if I push more than that it goes down straight to 4th and starts really pulling. Is there a way to push it so it kicks down to 5th instead? So far I have to do a big push and ease off immediately so it goes in 5th.

That's ok, I suppose, just a little unusual. Admittedly there's enough torque to accelerate even saying in 6th gear. Perhaps, it just feels slower that it is because it stays quiet.
 

·
Registered
Joined
·
421 Posts
Yeah, the whole skip-to-4th thing on the highway annoys me too. Old Fort Mtn on I-40W has mine doing this in a couple places, when 5th will pull fine anywhere up the mountain. If it would simply downshift the 5th then back to 6th when the grade eases, it'd be a lot less bothersome. I usually end up doing what you do (push-then ease off).
 

·
Premium Member
Joined
·
714 Posts
Discussion Starter #3
I think I am getting used to it. For me usually it takes some time to get in tune with an auto, so that's ok.
 

·
Registered
Joined
·
73 Posts
Hi All

It is not a problem or anything, just my curiosity.

In the city I can give the some moderate amount of gas and the 6sp kicks down a gear quite willingly and nicely. On the highway, however, it's different. I can't yet figure it out entirely. Seems like half of pedal travel will keep in 6th and if I push more than that it goes down straight to 4th and starts really pulling. Is there a way to push it so it kicks down to 5th instead? So far I have to do a big push and ease off immediately so it goes in 5th.

That's ok, I suppose, just a little unusual. Admittedly there's enough torque to accelerate even saying in 6th gear. Perhaps, it just feels slower that it is because it stays quiet.
With all these fly by wire cars and high powered computers, the tranny can react to many different inputs. These can be not just the fact that you pressed the gas pedal down a certain DISTANCE...they also monitor the SPEED that you pressed it down. If you press it FAST , sometimes it will downshift quicker.

My sister has a Volvo S40 Turbo....it has a brake "assist" for emergencies. It monitors not only how hard you push the brake pedal...but the TIME between your foot leaving the gas pedal and pressing the brake. It assumes an emergency is in progress if you do this action quickly ...and it starts applying the brake for you. So you can scare the bejesus out of your riders once in a while...it really stops in its tracks.

So these computers can assume a lot of things based not only on an action but how FAST the action is taken.
 

·
Premium Member
Joined
·
714 Posts
Discussion Starter #5 (Edited)
With all these fly by wire cars and high powered computers, the tranny can react to many different inputs. These can be not just the fact that you pressed the gas pedal down a certain DISTANCE...they also monitor the SPEED that you pressed it down. If you press it FAST , sometimes it will downshift quicker.

My sister has a Volvo S40 Turbo....it has a brake "assist" for emergencies. It monitors not only how hard you push the brake pedal...but the TIME between your foot leaving the gas pedal and pressing the brake. It assumes an emergency is in progress if you do this action quickly ...and it starts applying the brake for you. So you can scare the bejesus out of your riders once in a while...it really stops in its tracks.

So these computers can assume a lot of things based not only on an action but how FAST the action is taken.
that's what i am talking about. on my accord that I had before, how quick you push made a lot of difference. i've been trying to find out the proper input for 5th on the highway. Somethins I manage...I think...but not entirely sure. Most of the time the first half of the travel doesn't seem responsive though. However, if I push almost halfway, there's some engine pull even without shifting, so maybe the fact that it stays quiet adds up to this odd feeling, the car actually does accelerate.

It's all a matter of getting used to though, even 6-4th shift doesn't seem as unnatural as before, and it drops to 5th real fast if i ease off a bit. From that point on, with some finess I can keep the 5th a bit longer.
 

·
Registered
Joined
·
18 Posts
This is one of our early complaints, too--after one week. We live in a somewhat hilly area. If cruise is set, anything but a mild grade causes it to go to fourth, where if it would react a little quicker, it has plenty of power in fifth.

I had a 2001 Ram (318) and it was one of my major complaints. It would be down 5 mph on an uphill before it would get around to shifting, then it was down into 2nd and at redline for a few seconds before going up into 3rd and going on up the hill. Eventually, I would use the OD Off button like a manual to anticipate the hills.

Now, the 6 speed Malibu isn't as dramatic or as annoying as that Dodge, but in some ways is even more aggrivating, because my 02 Avalanche shifts exactly like I want it to every time. I have used the shift levers on the Malibu in steeper hills similarly to how I was shifting the Ram...not ideal.
 

·
Premium Member
Joined
·
714 Posts
Discussion Starter #7 (Edited)
for some reason it has been bothering me a lot less lately. each tranny has it's own personality and unless it does very unreasonable things as with your Ram it should be ok after getting used to perhaps.
 

·
Premium Member
Joined
·
714 Posts
Discussion Starter #8
I am beginning to get the downshifts to 5th. Last night and this morning I was able to do it quite many times on the highway. I think the correct input is a short and quick stub. Not a "push" but a "stab"- a push with a bit of release.

Btw, anyone knows if this tranny has any learning in it?
 

·
Registered
Joined
·
421 Posts
It seems to. Mine doesn't shift down as harshly or as often as it did when new. I believe it's learning my lighter-footed driving style. At least so far the way it reacts is consistent with the learning 4 speeds I've had from GM in the past. With those, my cars would hold higher gears longer, resist shifting down too far with a light application of the throttle, etc., after I'd been driving it for a few trips. Let my heavier-footed significant other behind the wheel for a couple trips and the tranny would become more hair-trigger, downshifting quicker and harder at light inputs.
 

·
Registered
Joined
·
180 Posts
Since I do not know the parameters for TCC I have to wonder if some are misinterpreting its unlock as a second gear like going from 6 to 4?
I have been able to go to 5 repeatedly while on the highway and think I might be moving accelerater a bit rapidly to what I perceive as the needed input.
 

·
Registered
Joined
·
3 Posts
I find the trans to be fairly annoying. I have an '09 LT2 V6 and the only time it shifts "correctly" is when you are on a flat road and accelerating slowly. If you get on it too hard from a standing start there can sometimes be a long hesitation, if you are on the highway and want to pass if you hit the accelerator to hard it downshifts to much causing the car to rev way too high and if you push down on the accelerator too softly it will not down shift and attempt to accelerate t at too low of an RPM. My last Malibu was an '04 LS V6 and I previously had a '99 LS 4 cyl with a 4 speed trans and they too would downshift too much when attemting to pass on the highway but that was understandable because they only had four speed trannys. The other problem is the trans does not downshift when decelerating forcing you to constantly use the brakes when going downhill. I also have a problem with torque steer especially on roads that have indentations form heavy truck traffic. If I accelerate hard the car pulls all over the place. Don't get me wrong. This car is head and shoulders above my other Malibus but the shift logic in the trans stinks. My other car is an '09 Infiniti G37XS with a 7 speed trans and it shifts perfectly every time no matter what I am doing and will hold it's speed going down hill without having to touch the brakes. The last thing I have to "vent" about is replacing the headlights. This is not a problem exclusive to the Malibu. It looks like my Infiniti will require the same amount of work. I wanted brighter lamps so I purchased Hella bulbs. What a project! You have to basically remove the front wheels, wheelwells and nose from the car to replace the bulbs! I feel this is way too involved for an average person to handle. I guess a lot of people wiill be paying a mechanic to just replace a headlight bulb....
 

·
Registered
Joined
·
180 Posts
I have an '09 LT2 V6 and the only time it shifts "correctly" is when you are on a flat road and accelerating slowly.

If you get on it too hard from a standing start there can sometimes be a long hesitation, if you are on the highway and want to pass if you hit the accelerator to hard it downshifts to much causing the car to rev way too high and if you push down on the accelerator too softly it will not down shift and attempt to accelerate t at too low of an RPM.

The other problem is the trans does not downshift when decelerating forcing you to constantly use the brakes when going downhill.

I also have a problem with torque steer especially on roads that have indentations form heavy truck traffic. If I accelerate hard the car pulls all over the place. Don't get me wrong. This car is head and shoulders above my other Malibus but the shift logic in the trans stinks. My other car is an '09 Infiniti G37XS with a 7 speed trans and it shifts perfectly every time no matter what I am doing and will hold it's speed going down hill without having to touch the brakes. ...
Hesitation from standing start. Some vehicles won't allow to the pedal starts because it is considered abusive and could make wheels spin. I don't know if this is one of them. As to revving too high, is it going red line? Otherwise it might be considered normal for vehicle when you want maximum acceleration. You might try varying the accelerator depress rate and backing off a little when it shifts to where you want it, as others have found that works.


You have not indicated where you live so we might grasp your hill situation. I hope they are not so severe that you have to slow way down so as to not outdrive your visibility. I have not yet figured out when engine braking is supposed to exist or if foot totally off accelerator will engage some of it or possibly light braking will add it. It would be nice to know.
I needed engine braking coming down mountain grade. It was a bit annoying because I was used to pulling the shifter from OD to D and if more was needed, just pull it another notch. To force enough engine brake, I had to reach over and pull it into M, then find the paddle shifter and work it. I had to use a combination of lower gear and braking. With a smaller engine you will not get as much engine brake, say compared to a NorthStar V8.


Torque steer. Overloaded truck wear grooves can be annoying to say the least. I have not yet experienced a major issue in that avenue. Torque steer has been little on my vehicle.
Are you running tires at correct inflation?
What size and type of tires do you have?
Has the alignment been checked and what are the figures?

I had a vehicle that handled such beautifully. It likely had more range of motion in the horizontal plane of suspension than many vehicles because of different design. Also the tires I had on it had soft sidewalls and usually looked low on air even when set correctly. The tires were decisively among the very best for the vehicle according to everyone who tried them. Rating was for handling, noise, response, and traction. When coming upon such grooves, you could literally feel the footprint of one side of the vehicle move while the other side tried to remain stationary. If it was a short problem, the vehicle would come right back to where it was. If it was long enough, then the other side of the vehicle would adjust for best tracking.
With the BU it might be difficult to acheive this because I think I read somewhere that the wheelbase for the front and rear are different. That would make either the front or rear react sooner.
You might improve the torque steer issue by adjusting the alignment. I don't know what the correct specs are for this car, but I suspect they don't have the correct figures at the dealer. They used chart for older BU with 4 speed.
Per that spec, the RS front gets more camber than the LS. I was told that was to help with pulling to the right on roads with crown. Such a setting might have an advantage when driving the oval as well. My driving, I'm likely to encounter crowns going both directions or just flat road. And the caster was set higher for the right than the left. If I were driving country roads where the most defects would likely occur toward the edge of the road, I think it would be better to have the higher caster toward the center of the road. Caster is intended to keep the wheel pulling the car straight and the more of it would be fine on perfect roads. However, when running grooves such as you are, minimum caster would probably help control.
If alignment is correct, the contact patch of the tire must also be equal from LF to RT. Rather hard to do with severe road grooves. It would take a tire that is able to flex enough in the sidewall and the tread to maintain full contact at all times.
Hopefully you can work it out. At least you do not have the feeling of play at the steering wheel.
 

·
Registered
Joined
·
180 Posts
Bobs 72:
Would you please look at tires for TPC number, assuming they are original. Also post with year, model, engine, tranny, and oe tire size.
Supposedly that TPC number is something GM developed and it should be used when replacing tires. One of the tests included in the testing is the ability of the tire to maintain straight line and the testing is for every GM model with specific TPC for equiped model.
 

·
Registered
Joined
·
3 Posts
Hesitation from standing start. Some vehicles won't allow to the pedal starts because it is considered abusive and could make wheels spin. I don't know if this is one of them. As to revving too high, is it going red line? Otherwise it might be considered normal for vehicle when you want maximum acceleration. You might try varying the accelerator depress rate and backing off a little when it shifts to where you want it, as others have found that works.


You have not indicated where you live so we might grasp your hill situation. I hope they are not so severe that you have to slow way down so as to not outdrive your visibility. I have not yet figured out when engine braking is supposed to exist or if foot totally off accelerator will engage some of it or possibly light braking will add it. It would be nice to know.
I needed engine braking coming down mountain grade. It was a bit annoying because I was used to pulling the shifter from OD to D and if more was needed, just pull it another notch. To force enough engine brake, I had to reach over and pull it into M, then find the paddle shifter and work it. I had to use a combination of lower gear and braking. With a smaller engine you will not get as much engine brake, say compared to a NorthStar V8.


Torque steer. Overloaded truck wear grooves can be annoying to say the least. I have not yet experienced a major issue in that avenue. Torque steer has been little on my vehicle.
Are you running tires at correct inflation?
What size and type of tires do you have?
Has the alignment been checked and what are the figures?

I had a vehicle that handled such beautifully. It likely had more range of motion in the horizontal plane of suspension than many vehicles because of different design. Also the tires I had on it had soft sidewalls and usually looked low on air even when set correctly. The tires were decisively among the very best for the vehicle according to everyone who tried them. Rating was for handling, noise, response, and traction. When coming upon such grooves, you could literally feel the footprint of one side of the vehicle move while the other side tried to remain stationary. If it was a short problem, the vehicle would come right back to where it was. If it was long enough, then the other side of the vehicle would adjust for best tracking.
With the BU it might be difficult to acheive this because I think I read somewhere that the wheelbase for the front and rear are different. That would make either the front or rear react sooner.
You might improve the torque steer issue by adjusting the alignment. I don't know what the correct specs are for this car, but I suspect they don't have the correct figures at the dealer. They used chart for older BU with 4 speed.
Per that spec, the RS front gets more camber than the LS. I was told that was to help with pulling to the right on roads with crown. Such a setting might have an advantage when driving the oval as well. My driving, I'm likely to encounter crowns going both directions or just flat road. And the caster was set higher for the right than the left. If I were driving country roads where the most defects would likely occur toward the edge of the road, I think it would be better to have the higher caster toward the center of the road. Caster is intended to keep the wheel pulling the car straight and the more of it would be fine on perfect roads. However, when running grooves such as you are, minimum caster would probably help control.
If alignment is correct, the contact patch of the tire must also be equal from LF to RT. Rather hard to do with severe road grooves. It would take a tire that is able to flex enough in the sidewall and the tread to maintain full contact at all times.
Hopefully you can work it out. At least you do not have the feeling of play at the steering wheel.
I think you have misunderstood my steering issue. The tires are factory on 18" factory rims. The car tracks straight as an arrow as long as you are not accelerating aggressively. If you do decide to accelerate more aggressively that is when the car tries to wander from left to right. As far as the trans goes we can try to figure out how to make it do what we want but as far as I am concerned it is an automatic and should do everything automatically.
 

·
CMF Honorary Member
Joined
·
4,326 Posts
The car tracks straight as an arrow as long as you are not accelerating aggressively If you do decide to accelerate more aggressively that is when the car tries to wander from left to right.
Sounds like typical/normal torque steer to me....
 
1 - 15 of 15 Posts
Status
Not open for further replies.
Top