OldChevyNut

Because I no longer own a GM vehicle, I'll be leaving the forum. But as a last response, Yes, the GM profile system, the GM programming algorithm and the rather large memory capability of the control unit means that driver habits are recorded and used in slightly altering vehicle operation. Unfortunately, because the current trend is "fuel economy", this usually means that "adaptive" translates to sluggish. In my current vehicle, an F-150 5.0 10 speed, it drove great to begin with, but after the first 1000 miles or so it became sluggish when accelerating from lights, did more gear skipping (non-sequential up-shifting), and generally required mode changes (Eco, Normal, Sport, etc) to get some of the performance back. And the characteristics of "adaptive" seem to permanently remain as long as the control unit has power. Simply turning off the engine does nothing to change any of the stored data. However, we have learned that we CAN force the control unit to begin "re-learn" by removing and re-inserting the power fuse for the controller (in our vehicle it's fuse 109 I think, but check your own vehicle system). This basically gets rid of the sluggish operation in "Normal" mode until re-learning is once again completed. But then again, I have no problem driving conservatively and saving fuel so I think I let it learn and leave it that way. If more performance is desired, I'll simply switch modes. I wish you all the luck in the world with your GM vehicle.

For worldaccordingtojim, I disagree about how you regard the transmission "learning". It's actually referred to an "Adaptive" transmission, it's been around for a couple of decades, and it's not alone. Ford 8 speed and 10 speed have the same feature, as does the new GM Allison 10 speed and the 8 speed ZF 8 used in many Ram products and European vehicles. In 2019 GM vehicles, I'd highly recommend you setup your operator profile and assign it to a key fob ID, so the vehicle can begin learning how you operate the vehicle. From the time you establish the profile, your driving habits will be recorded and used for altering transmission characteristics during vehicle use, such as shift points. If a second person operates the vehicle, that person should also create their own profile and assign the other key fob ID. If more than 2 persons operate the vehicle, the 3rd (and any other operators) may also need to create profiles and assign a specific key fob ID, otherwise, as they operate the vehicle the way they want, that data may indeed corrupt the profiles of operator 1 or 2. If you don't establish a profile, the factory default settings are used from the moment the vehicle was taken out of "Transport" mode during dealer prep. By the way, the operator profiles save a lot more data than just usage information, like all of the available entertainment (AM, FM, Syrius) and communication (Apple, Blue Tooth, etc) preferences. So once you understand what it can provide, the operator profile can be a very desirable feature.

For wizard4878, Glad to hear your vehicle is doing good, and I wish you the best of luck in the future. Actually, ALL TSB's on 8L45 and 8L90 have been cancelled. The 6 speed was much more likely to shudder, usually going from 2nd to 3rd and having problems selecting which gear. The 8 speed had a similar problem, plus others. But since the introduction of some "better-late-than-never" product changes, proper diagnostic test equipment distributed to every dealer, and the still-continuing re-formulation of a suitable transmission fluid, vehicles manufactured after 2-16-19 and equipped with a 8L45 or 8L90 are SUPPOSED to be trouble-free. Too bad mine wasn't, but it's gone now (buy back following litigation) so I shouldn't speak badly of the dead. By the way, the 4L60E was fairly reliable, but the 4T60(E) was a major reliability nightmare for GM.

5.7 or 6.4 Hemi with a ZF 8 (8F70/8F75) is a great package. Basically a 6 speed unit with 7th and 8th being OD for highway use. High first gear ratio is good for hauling/towing, which is what a truck is for, right ?? But real-world mpg numbers in the 13 range, high MSRP's in the 60K-85K range, and marginal/poor dealer services make buying one a chancy proposition. After renting a well-equipped Laramie 5.7 for 4 days to do a real test drive, I didn't buy.

For Snuff: I no longer own a GM vehicle, and currently own a Ford F-150 XLT Crew 5.0 10-speed plus the usual goodies. I have no problems of any sort with the vehicle (except for keeping it clean), but have just over 1100 miles on it. Because I received a notification regarding this post, today I spoke with 2 of my former colleagues at the GM Transmission plant in Romulus, Michigan (where I was employed prior to retirement). From what I've been told, GM engineers keep track of Ford-reported issues because the GM 10 speed unit is functionally nearly identical. Ford has reported low-occurrence issues with rough shifting and "gear searching" in less than 2% of vehicles with 10 speed transmissions returned for service. I've been told both issues have been resolved, with a single TSB issued for the rough shifting issue. Like the GM 8 speed, the Ford 10 speed is an adaptive unit, where the user driving habits are recorded and used when the same user operates the vehicle, and Ford finds that when the vehicles have been driven for approximately 800 miles or more, the occurrence of owner-reported "gear searching" issues is virtually eliminated. Because I know the Ford 10 speed has been getting very positive results from using the 10 speed in F-150 and Ranger vehicles, and that I did considerable research into history of the unit prior to my recent purchase, I would recommend it without reservation. I cannot say the same for any previously existing version of the GM 8 speed unit. However, I was told the NEW GM 8 speed transmission, earmarked for use in Silverado 2500 vehicles, is a new design, not just a warmed-over version of the 8L90. I'm also told the new Allison 10 speed unit earmarked for Silverado 3500 vehicles is testing to be far superior to the existing 8L90 8 speed or even the GM 10 speed. And I was told that certain 2020 GMC Sierra 1500 models will offer the GM 10 speed as an option, even on 5.3 liter engines but not with 2-wheel drive. I was not told if a similar option would appear for the 2020 Chevrolet version. I'm not sure if any of the above helps with your 2019 decision, but it's about all I could find out on short notice. But if it were me, and I needed a truck now, it would be the Ford. If I could wait 4-5 months, I'd check-out the 2020 GMC Sierra with a 10 speed option. I would not buy a GM 2019 with an 8 speed under any circumstance. BTW, here's a couple of the news release links I found that back-up the info I was given on the 2020 GMC Sierra 1500. https://www.cnet.com/roadshow/news/2020-gmc-sierra-1500-technology-powertrain-updates/ https://media.gmc.com/media/us/en/gmc/home.detail.html/content/Pages/news/us/en/2019/may/0517-gmc.html

I agree with Hillwood's statement 100%

As a comment for Mr. Rutherford's persistent vibration problem, the vehicle should be capable of reaching the computer-controlled maximum-allowed speed of about 125 mph without noticeable vibration. Just think, cop vehicles do it all the time, but their speed limiter is usually set for 140 mph or higher. Vibration such as you describe is generally caused by a rotating mass. Objects with a small diameter usually develop less vibration than objects of a large diameter, so when trying to find out what causes a given problem, start with checking things with large diameters. In the transmission area, the object having the largest diameter is the torque converter. But then again, the transmission may not be the only source of excessive vibration. In most cases that I'm aware of, tires and suspension components are the most common causes of high vibration levels. Virtually every dealer can check vibration levels by attaching sensors at specific points on a vehicle, then using a fairly common device that picks-up the sensor readings under a road test and displays results by the frequency (in Hz) and intensity of the vibration. Then the tech looks into a book, finds what can cause vibration at the noted frequency, and then further work is directed at the suspected vibration source. At least, that's how it's supposed to work, and it can be a laborious and costly process of testing, fixing, retesting. The dealer(s) should have started by testing the vehicle as above, then simply fixing the vibration sources and retesting until all vibration levels are withing factory levels. But by your comment, this didn't happen. So you're probably getting a dealer doing some amount of work with tires, driveshafts, etc, without doing any testing and having no idea what the real problem is. And when they think they've done enough, you'll get statements like "normal vibration" simply because the dealer doesn't want to spend the time and money to fix it. Under such conditions, the best advice I can give is to continue taking the vehicle to the dealer, or a different dealer, documenting the condition and the vehicle mileage when the issue was first reported for warranty purposes, then insist the dealer test and repair the problem and even put "normal vibration" statements in WRITING. Do this many times, keeping all records associated with each dealer visit, and after many attempts to correct the condition, if problems persist, file for resolution via "lemon law" mechanisms such as arbitration or even litigation. But I wouldn't continue to drive any vehicle with such an obvious defect. I would insist they either fix it or buy it back. But then again, that's just me.

There are reasonably available resources that can be used to estimate past and future vehicle resale value trends. Among them is KBB.com (check it out ?), but I'm sure there are many others because prior to retirement I used them. Since 2017, Silverado has gone from 3rd to 4th, and for many it seems that the product line will continue it's current downward trend as far as vehicle resale value. And for the Colorado/Canyon platform, according to the KBB data, it seems the downward slope is much steeper, especially in 3rd qtr 17. I got rid of my GM products. And prior to the events of the recent past I would have said to anyone else "decide for yourself", but because I have gained so much objective evidence, I sometimes feel it's appropriate to voice my opinion. I also personally feel that GM is continuing to produce this transmission because there is such a large percentage of potential buyers that are still willing to purchase marginal or defective product. Perhaps because their dad always had GM's, perhaps their friends like them, maybe because they simply think it looks cool, whatever. But as long as GM can produce marginal or defective products and sell it, they'll have little or no motivation to correct issues. As a young engineer fresh out of college I once worked for GM, and I enjoyed my tenure with them. However the world has changed, and perhaps I'm unrealistic to expect quality and reliability to be something more than long-forgotten words. But, to use plain english, I was really pissed when a brand new Canyon couldn't go 1100 miles before the transmission died. So if you know anyone with a low mileage 2011 Lincoln Town Car, let me know and I'll buy it and drive it for another few hundred thousand miles, or maybe more ?

Perhaps I've overstated the truth, but because GM knowingly produced product which included serious functional defects, can facts and truths EVER be truly be overstated when consumers continue to suffer and management continues to bask on sunny beaches ??? I think not ...

From information available as of the date of this comment, MQE 8-speed will be options used in 2.7 I4's and 5.3 V8 with DFM. MYC 6-speed will be standard with the same engines under RPO's LV3 and L82 (basic light duty vehicles). A GM version of the Ford 10 speed has been in use in certain vehicles equipped with 6.2 V8's since 2017, with significant problems beginning to appear. Beyond slight trim and and option changes, nothing will change in drive-trains for mid-sized trucks until a planned re-design to be introduced in 2022. At that time, a GM light-duty version of the Ford 10 speed MIGHT be an option. In case you didn't already know, all the TSB's for the 8L90 and 8L45 have been cancelled for vehicles manufactured beyond a specific date (2-16-19 ??). GM now says that "It's fixed", or "There is nothing wrong", or "It's NORMAL". Most dealers won't even look at it unless they see a warning light on the dash or codes readable through the OBD port. And as of 4-10-19, formulations of transmission fluids continue to be revised. For anyone purchasing a GM vehicle, in virtually every model transmission you should be prepared for significant transmission problems. And because the problems have become so public, you can expect the resale values of a GM vehicle to be much lower than similar vehicles from other makers. Any way you look at it, you lose.

Windows open, smells go away faster, windows closed, smells last much longer. Unfortunately, most owners drive with all windows up all the time. If you have the option to "recirculate" inside air on your climate control, leaving it off to allow outside air into the vehicle will help dissipate the smell, and in fact, serves the same purpose as leaving a window open a slight amount. Many think that the smells come from polymer-based materials (plastics) used in vehicle interiors, but many studies have proven this to not be the case. The great majority of smells come from other sources, even from natural materials used in the vehicle. But then again, so many new materials are created every year, it's becoming much harder to tell exactly where the smells come from, and whether or not the materials being inhaled could be potentially harmful.

It is well known, and even acknowledged by GM, that the problems with this transmission cannot be fixed. Therefore, as soon as possible and with as few miles on the vehicle as possible, take it back to a dealer and request the defect be repaired. Do this several times, keeping all records of when, where, action taken (even if none), any advice or comments made by dealer persons, and if possible, record everything on video with sound. Remember it's not the dealers fault you bought a vehicle with a problem that cannot be fixed by any means, but the dealer is the one that's stuck with trying to fix it. Obtain all the information you can find on this problem, and even similar problems in other models (because the same transmission is used in multiple other vehicles), obtain all applicable GM TCB's (such as TCB 18-NA-177 and TCB 18-NA-355) that have any bearing on the problem, and then after a "reasonable number" of repair attempts apply for Arbitration according to the requirements applicable in your state. In Arbitration, which is free to the vehicle purchaser, present all evidence regarding nature of the problem, past history and the manufacturers inability to correct these serious defects, evidence that the issue exists in the vehicle you purchased, and the history of repeated attempts by dealer(s) to fix the problem but that the problem still exists. When is all is said and done, you may be given a refund of the vehicle purchase price, a replacement vehicle having the same configuration and options, a decision to return to a dealer for further repair attempts, or no other action or remedy. In the case of the 8L45 / 8L90 transmission issues, arbitration in many states has already ordered refunds and replacement vehicles, as the problems with this model transmission have been around for so long and are so well documented. In any event, Good Luck.