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2008 Transmission Issues?

13K views 27 replies 17 participants last post by  Kloogee 
#1 ·
Does anyone have any transmission issues with down-shifting on the 2008 Acadia? My new Acadia is on order, and due to arrive mid-January 2008. Should I expect to find the issue resolved with my new 2008 Acadia, or should I have to ask the dealer to update the software?

Thanks,
mritter
 
#2 ·
There are no updates for the 2008 models built after Aug 2007 so yours will come off the line with the most current software. I have no complaints with my '08 which was built the 3rd week of Aug. In fact, the powertrain combo in our Acadia is actually more responsive than the 6.0L/4-speed in my Silverado.
 
#4 ·
GeoHawk said:
There are no updates for the 2008 models built after Aug 2007 so yours will come off the line with the most current software. I have no complaints with my '08 which was built the 3rd week of Aug. In fact, the powertrain combo in our Acadia is actually more responsive than the 6.0L/4-speed in my Silverado.
thats a motivator.... hopefully mine arrive without the glitches... i got all fingers crossed along with my :tard:
 
#5 ·
I've got a Nov 08 built Acadia and I personally think it still could use some work. I didn't drive a pre-flash vehicle, so I've got nothing to compare, but I really find that I'm constantly aware of the transmission far more than in any other vehicle I've ever driven. It just feels like I've got to try to make it do what I want it to by adjusting the throttle rather than it just always being in the sweet spot. I think the big issue is that it is tuned to try to maximize fuel economy rather than for optimum driving performance. I really don't fault them for that as that is the reason many of us purchased a Lambda, but I really am aware of the transmission as I drive it. It really is the one area I'm not 100% happy with thus far in my 1 month relationship with my Acadia. I'm really disappointed in that as I always thought that the more cogs a transmission has in it that it would be a sweeter drive because it would always be in its sweet spot. That just isn't the case in my Acadia.

I've mentioned on another thread that I think another 25HP & 25 lb/ft (or better yet 500 lbs lighter) would really help it out and make it feel much smoother. But of course more HP likely means worse MPG, so it is a tradeoff. I wish they had a "sport/economy" toggle switch that would allow you to choose your transmission mapping. That way you could get the best of both worlds. (And yes I do have the tow/haul button, but that isn't the same.)
 
#6 ·
Someone said on this forum that transmission is learning as your driving. I was skeptical about this statement, but I'm closed to 2000 mile and I admit it's true. Today for first time, I had different an experience with my car, it was respond as you need it. It's like you think a need lower gear and it does.
I'm not sure why it started doing it, may be weather or transmission really adjusted to my driving or different fuel.
 
#7 ·
SioXie said:
GeoHawk said:
There are no updates for the 2008 models built after Aug 2007 so yours will come off the line with the most current software. I have no complaints with my '08 which was built the 3rd week of Aug. In fact, the powertrain combo in our Acadia is actually more responsive than the 6.0L/4-speed in my Silverado.
thats a motivator.... hopefully mine arrive without the glitches... i got all fingers crossed along with my :tard:
Since the latest flash for 07's 3 months ago that the new 08's have, mine shifts when I feel it should shift and is pretty smooth and responsive when it should.
Some people are unable to get used to the fact this vehicle is a 6 speed, V6, pulling 4000lbs. Some didn't test drive to find out if this is the engine and tranny they wanted before buying. Sioxie, if you are not a knit picker like SOME with this combo and should have purchased different vehicle, you will love the new performance coupled with mpg of the Acadia. Hopefully you have thoroughly test driven and like per your satisfaction, otherwise go for the Denali for power like some have.
 
#8 ·
vad1819 said:
Someone said on this forum that transmission is learning as your driving. I was skeptical about this statement, but I'm closed to 2000 mile and I admit it's true. Today for first time, I had different an experience with my car, it was respond as you need it. It's like you think a need lower gear and it does.
I'm not sure why it started doing it, may be weather or transmission really adjusted to my driving or different fuel.
I'm sure ours is quite confused since my wife and I (who have very different driving styles) have been swapping vehicles back and forth the last couple of weeks due to the holidays and family being in town.
 
#9 ·
teetertotter said:
Since the latest flash for 07's 3 months ago that the new 08's have, mine shifts when I feel it should shift and is pretty smooth and responsive when it should.
Some people are unable to get used to the fact this vehicle is a 6 speed, V6, pulling 4000lbs. Some didn't test drive to find out if this is the engine and tranny they wanted before buying. Sioxie, if you are not a knit picker like SOME with this combo and should have purchased different vehicle, you will love the new performance coupled with mpg of the Acadia. Hopefully you have thoroughly test driven and like per your satisfaction, otherwise go for the Denali for power like some have.
I don't understand when people make comments about it being a 6 speed as if that is an excuse. Maybe I'm completely wrong, but when you've got more cogs in the tranny, the more likely it should be in its sweet spot at all times. This is because each of the gears should be designed to work in a more specific rpm range / load characteristic. Unlike the old days when there were only 3 cogs and each cog had to handle a very large range of rpm/load.

Anyways, I'm not trying to say that I hate the tranny. Not at all. I just think that GM still has quite a bit of refining to do to make it buttery smooth and intuitive. So far, I love everything else about my Acadia.
 
#11 ·
Kloogee said:
Anyways, I'm not trying to say that I hate the tranny. Not at all. I just think that GM still has quite a bit of refining to do to make it buttery smooth and intuitive. So far, I love everything else about my Acadia.
While I have the total opposite opinion about the transmission in that I think it's fine for me without any changes, it just reinforces the fact that we all have differing opinions and this forum obviously surfaces those varying opinions. Many times I do not agree with magazine/web reviews of cars or anything else. Not any one opinion is totally right or wrong(usually).

However, I do think this points out the fact that anyone contemplating the purchase of a new Acadia should check out these things for themselves during several test drives. Make decisions on the basis of your own driving impressions and use this forum as a jumping off point for issues to look at. Unfortunately if you buy a new model early, before a forum like this gets established, you miss the benefits of the forum.
 
#12 ·
Snoguy said:
Kloogee said:
Anyways, I'm not trying to say that I hate the tranny. Not at all. I just think that GM still has quite a bit of refining to do to make it buttery smooth and intuitive. So far, I love everything else about my Acadia.
While I have the total opposite opinion about the transmission in that I think it's fine for me without any changes, it just reinforces the fact that we all have differing opinions and this forum obviously surfaces those varying opinions. Many times I do not agree with magazine/web reviews of cars or anything else. Not any one opinion is totally right or wrong(usually).

However, I do think this points out the fact that anyone contemplating the purchase of a new Acadia should check out these things for themselves during several test drives. Make decisions on the basis of your own driving impressions and use this forum as a jumping off point for issues to look at. Unfortunately if you buy a new model early, before a forum like this gets established, you miss the benefits of the forum.
AMEN.... ;D
 
#14 ·
mritter said:
Does anyone have any transmission issues with down-shifting on the 2008 Acadia? My new Acadia is on order, and due to arrive mid-January 2008. Should I expect to find the issue resolved with my new 2008 Acadia, or should I have to ask the dealer to update the software?

Thanks,
mritter
Oh yes there are issues with 2008's. I have a 2008 Outlook XR AWD and the transmission programming is a nightmare! It's always in the wrong gear. I find that I have to shift it manually and keep it in 4th gear around town. Mine shifts into third so early that it is dangerous to drive smoothly among traffic. Another problem is that it won't hold 6th at highway speeds if there is a slight uphill or headwind I have to keep it in 5th or else it downshifts constantly and then immediately back up again. It doesn't just downshift to 5th, but more like a 4.5 gear or something. So on the highway it goes like this.... cruising along @ 1800 rpm, here comes a slight uphill that you can barely see, downshift to 3000 rpm (vehicle lunges ahead) followed by immediate upshift to 2400 rpm and then another upshift back to 1800rpm. ... a few minutes later and it does it all again. The only way to avoid this is to drive in 5th, unless you have a tailwind or are driving downhill. When people tell me they are considering a Lambda, I tell them to buy something else!
I hope GM does something about this real soon. I am generally impressed with the Lambdas but this transmission shifting is terrible!!
 
#15 ·
Z06jerry said:
...So on the highway it goes like this....cruising along @ 1800 rpm, here comes a slight uphill that you can barely see, downshift to 3000 rpm (vehicle lunges ahead) followed by immediate upshift to 2400 rpm and then another upshift back to 1800rpm. ... a few minutes later and it does it all again...
Mine (08 Acadia 2WD) does the same thing.
 
#17 ·
f3qu3t said:
Z06Jerry, what is your build date for your '08? If it's before mid August, have you had the transmission flash done?
Where do I find the build date? There is a decal on the drivers door with 09/07 on it but it doesn't specifically indicate that this is the build date. My Dealer told me that there was no transmission update for '08's.
 
#18 ·
Z06jerry said:
f3qu3t said:
Z06Jerry, what is your build date for your '08? If it's before mid August, have you had the transmission flash done?
Where do I find the build date? There is a decal on the drivers door with 09/07 on it but it doesn't specifically indicate that this is the build date. My Dealer told me that there was no transmission update for '08's.
Jerry,

The early 08's were eligible for the update, those that were built in June, July, and early Aug 2007. If the last 8 digits of your VIN# are between 8J100641 and 8J126062 (these are for the Outlook only, the Enclave and Acadia have different VIN# breakpoints), then you have the old software calibrations and could possibly benefit from the update. But it appears yours was built in September 07, so you should have the most current software. My Acadia does this shifting as well (maybe not to your extent, though), but I do notice that the shifting is much less frequent if I'm not using cruise control.
 
#19 ·
I have to echo the negative comments about the tranny. I have an 07 with the flash. I drove an acadia for about 20 minutes before I purchased one. On and off freeways....city driving... etc. Didn't have a problem with the transmission. It is one of the reasons I purchased the car over the Ford Edge. The edge seemed underpowered and the tranny was noticeable.

I noticed the obtrusive acadia tranny the minute I drove it off the lot. At first I thought it was because of the number of gears.....six gears....more shifting. An early reflash helped a little and the final flash this summer helped more but it still bothers me. If I try to accelerate onto a highway the car actually slows down when it hits third or fourth gear. I have to remember to keep giving it more and more gas. It doesn't have a smooth power curve.

I am not a kid. I have been driving cars a long time. I have never had a tranny that behaved this way. Maybe its because the car is underpowered....maybe its the 6 gears. For those of you that don't notice the issue.....that is great. Some people like myself are very sensative to vibrations and noises in a car. I hear and feel when the tranny is lumbering....being in too high of a gear to apparently save gas. I am thinking about pulling the battery to see if the tranny will relearn my driving......this time I want to drive more agressively so it gives better performance.

Will disconnecting the battery cause the tranny to relearn?
 
#20 ·
GeoHawk said:
Jerry,

The early 08's were eligible for the update, those that were built in June, July, and early Aug 2007. If the last 8 digits of your VIN# are between 8J100641 and 8J126062 (these are for the Outlook only, the Enclave and Acadia have different VIN# breakpoints), then you have the old software calibrations and could possibly benefit from the update. But it appears yours was built in September 07, so you should have the most current software. My Acadia does this shifting as well (maybe not to your extent, though), but I do notice that the shifting is much less frequent if I'm not using cruise control.
GeoHawk, My vin # ends with 8J149032, after the cutoff. I suspect awd's are more prone to the shifting problem. GM probably should've had a shorter final drive ratio for awd's to compensate for the additional weight driveline losses. I find the most annoying shifting problem to be the premature upshifting (in normal driving) especially into 3rd gear and the lag in acceleration caused by this. I have to be extra careful in traffic as I am often unable to merge smoothly due to the lag and the disconnect between the throttle position and the transmission operation. Surely GM engineers can do better than this, I have to shift manually because the automatic shifting is so crappy. On the highway I also find that there is less downshifts when I am not using cruise, and If I am driving into a headwind I have to leave it in 5th to avoid constant and repeated downshifts.
 
#21 ·
newz54 said:
I have to echo the negative comments about the tranny. I have an 07 with the flash. I drove an acadia for about 20 minutes before I purchased one. On and off freeways....city driving... etc. Didn't have a problem with the transmission. It is one of the reasons I purchased the car over the Ford Edge. The edge seemed underpowered and the tranny was noticeable.

I noticed the obtrusive acadia tranny the minute I drove it off the lot. At first I thought it was because of the number of gears.....six gears....more shifting. An early reflash helped a little and the final flash this summer helped more but it still bothers me. If I try to accelerate onto a highway the car actually slows down when it hits third or fourth gear. I have to remember to keep giving it more and more gas. It doesn't have a smooth power curve.

I am not a kid. I have been driving cars a long time. I have never had a tranny that behaved this way. Maybe its because the car is underpowered....maybe its the 6 gears. For those of you that don't notice the issue.....that is great. Some people like myself are very sensative to vibrations and noises in a car. I hear and feel when the tranny is lumbering....being in too high of a gear to apparently save gas. I am thinking about pulling the battery to see if the tranny will relearn my driving......this time I want to drive more agressively so it gives better performance.

Will disconnecting the battery cause the tranny to relearn?
I have an 08 that was built in Nov 07, so it should definitely have all the latest updates. I would describe my tranny's behavior exactly as you do. As you mention, it feels like there are several points where it seems to actually slow down (especially if there is even a hint of an incline at all). The tranny programming definitely is set to try to optimize MPGs over proper driving behavior. I love my Acadia otherwise, but this behavior drives me nuts. I've been driving for a long time as well and have had all sorts of different vehicles with both manual and auto trannies with anywhere from 3 to 6 cogs in them. And I am far more aware of the tranny in the Acadia than i've ever been in any other vehicle.

I find myself moving the gear lever to L quite frequently so that I can get a better driving experience. I'm glad a lot of you are happy with the way the tranny works, but obviously if so many people are talking of the same behavior, then GM really should be putting some more effort into it. Unfortunately, I doubt we'll get much reprieve on this issue as I'm sure changing the programming significantly could have an impact on the EPA MPG estimates.
 
#22 ·
2008 Outlook FWD - Though i do notice that the transmission shifts up quickly, i assume to save MPG, i do NOT have the problems that some of you have mentioned. For example, traveling up a hill the trans shifts just how i would expect. The only place i notice anything "out of the norm" is when you want to hammer on the gas when you are already moving, there seems to be a lag while it is shifting, nothing horrible however. I remember having a Audi Turbo that had similar traits, only then we called it Turbo Lag.

Mike
 
#23 ·
Z06jerry said:
GeoHawk, My vin # ends with 8J149032, after the cutoff. I suspect awd's are more prone to the shifting problem. GM probably should've had a shorter final drive ratio for awd's to compensate for the additional weight driveline losses. I find the most annoying shifting problem to be the premature upshifting (in normal driving) especially into 3rd gear and the lag in acceleration caused by this. I have to be extra careful in traffic as I am often unable to merge smoothly due to the lag and the disconnect between the throttle position and the transmission operation. Surely GM engineers can do better than this, I have to shift manually because the automatic shifting is so crappy. On the highway I also find that there is less downshifts when I am not using cruise, and If I am driving into a headwind I have to leave it in 5th to avoid constant and repeated downshifts.
Dito!!!! It is hell, and then I have 2 ski boxes on top. The worst is the lag between 30 and 40 mpg, it is dangerous. The lag last over a second!!! I tried a brand new Outlook before I bought my Acadia and it did the exact same thing. Mine was built 10/07 and my vin ends up by 8J181913. On the cruise I use the tow mode, it helps a little bit. The 6 th speed doesn't stay more than 25 sec if the is a slight hill. Downwind and downhill it is perfect. Headwind + hill, it never stop playing. Very uncomfortable for the passenger. My girlfriend told me to be less agressive while driving... If I don't step on it, I'll die driving.

Feels like the economy mode. Good for straight highways. I wish there would be a perf mode.

I had an Avalanche before and the tranny was perfect!!

This is the only draw back for this car now. I have 2500 miles on it.

My 2 cents.
J
 
#24 ·
I'm thinking that those of us that are unhappy with the transmission performance need to all start calling the GM customer service hotline to bring this to their attention. I'm thinking that may get their attention more than us complaining on a forum that I'm sure they don't officially monitor.
 
#25 ·
I recently leased a 2008 Acadia. Like Z06Jerry reports and many others, the transmission shifting drives me crazy. Everything about the vehicle is great with the exception of the transmission shifting. I find this vehicle puts me in danger when trying to merge with highway traffic due to the slow response of the tranny. Accelerating from 40 km and upwards through 60, 70, 80 km's is one big kick to the pedal and whiplash to all the occupants of the vehicle. I feel that I am continually hammering on the throttle (and that takes alot) to get the vehicle to shift and pick up speed. The hard and sudden down and upshifting that occurs on the highway when the cruise is engaged drives me nuts (1800 rpm to 3000 rpm and back again). I have driven Ford Explorers for the last 9 years (3 year leases) and nothing beats the V8 and the get up and go of Explorer. Never had to persuade the tranny to shift. I did it on its own unless I was wanting to get moving in a hurry. This Acadia might be be more comfortable, but I'm kicking myself now that I'm getting to know this tranny more. In addition, the gas mileage is far from what they report. When friends ask if I would recommend the Acadia, I tell them to look elsewhere i.e CX-9 if your looking for better performance.
 
#26 ·
zoom said:
I recently leased a 2008 Acadia. Like Z06Jerry reports and many others, the transmission shifting drives me crazy. Everything about the vehicle is great with the exception of the transmission shifting. I find this vehicle puts me in danger when trying to merge with highway traffic due to the slow response of the tranny. Accelerating from 40 km and upwards through 60, 70, 80 km's is one big kick to the pedal and whiplash to all the occupants of the vehicle. I feel that I am continually hammering on the throttle (and that takes alot) to get the vehicle to shift and pick up speed. The hard and sudden down and upshifting that occurs on the highway when the cruise is engaged drives me nuts (1800 rpm to 3000 rpm and back again). I have driven Ford Explorers for the last 9 years (3 year leases) and nothing beats the V8 and the get up and go of Explorer. Never had to persuade the tranny to shift. I did it on its own unless I was wanting to get moving in a hurry. This Acadia might be be more comfortable, but I'm kicking myself now that I'm getting to know this tranny more. In addition, the gas mileage is far from what they report. When friends ask if I would recommend the Acadia, I tell them to look elsewhere i.e CX-9 if your looking for better performance.
did you test drive before you lease?
 
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