I'm new here , so if I'm posting this in the wrong place I apologize.
I've read a lot about the TC problems that occur with the AFM and the A 8 transmission. I own a 2017 Z51 Stingray 3lt. I bought it with 7100 miles on it and I've put almost 8000 miles on it in the 1 1/2 that I've owned it. I ordered the Range tech unit and received it today. Currently, I have no issues or shudder going on. Was trying to avoid issues by installing the Range unit. I've read that most of the issues appear between 10k and 20k miles. I'm not really sure what goes wrong with the TC, but does it just go bad or is it possible that mine may already be damaged even though I'm showing no signs or symptoms. Will installing the Range device just prolong the inevitable since I'm installing it so late in the game. Wondering if I'm doing the right thing .

 

The TC "issues" have more or less been created and perpetuated by this (and a couple other) forums. The issue isn't a problem with the TC and a range device won't do anything but make you feel better about what the forum told you to do. We work on 115-150 Corvettes per month, which is significantly more than most large volume dealers. That doesn't count the dozens of trucks, Tahoes, EscaIades, and everything else with 8 speed transmissions. I think we've replaced ONE single TC and it wasn't related to shudder. I've read several stories of dealers replacing more than one TC on a vehicle only to have the shudder come back because the TC isn't the problem. The fluid that gets flushed out with a TC replacement is what made the condition temporarily better. Now that we've have the latest fluid available for the last several months, it seems to fix the shudder for a longer period of time.

Install the range or not, it won't matter. I would either leave it alone or go get your fluid flushed per the latest bulletin under warranty and have fun with the car.

 

"... and have fun with the car." MOST importantly, do THAT!

Every issue would seem common to nearly every car, instead of extremely infrequent, if one only went by forum posts, for anything of any make or model.

 

Contrary to what JoeWhodat stated there has yet to be anyone who has used the Range Device who had encountered the dreaded shutter.

As for me, I used the range device for two of the four years I have owned my C7, the last two years I have not used it but driven 100% of the time in manual mode, using the paddle shifters.

 

There was at least one guy here that claimed to have had issues even with the use of a range device, but it is rare. Hell, I experienced shudder in my 2017 Caddy ATS A8 and it does not have AFM (2.0T engine). Dealer changed the fluid and it was back to normal.

I run my 2015 Z51 in manual most of the time and have yet to have shudder and it is still running stock trans fluid.

 

I have been using the Range Technologies AFM Disabler since my 2019 had about 500 miles on it. Don't know whether or not it will prevent the dreaded shudder but, for my money, it is well worth it just to keep the car from going into V4 mode. The car has about 1,400 miles on it now and no shudder. Regardless, I plan to have the new transmission fluid installed in the next couple of weeks. May not be necessary but it is worth it for peace of mind.

 

Richie, you are right it is not the torque converter , if you work on so many then you are aware of something called torque converter slip and how the lockup clutch is pulsed... and surely you know that converter is set to slip more and pulse more in 4 cylinder mode than in V8 mode .... which is exactly why the Range works for most of us ....by keeping it V8 mode we are reducing the number of engagements and disengagements the converter experences .. sure the friction modifier in the old fluid probably was not right, ( not believing that hydroscopic bull crap line as they have been making fluid a long time and now all of sudden it absorbs water ...) but AFM is not ready for prime time and if you work for a GM dealer you know they have been trying to perfect it since the days of the 4 6 8 Cadillac motor which was a miserable failure and they still dont have it right ..its all about Corp Cafe MPG regulations
just my two cents ..
Dave

 

From the mouths of experts, "GM, can you AT LEAST thicken the syrup (new, improved tranny fluid) to get us through the warranty period!!!" Not: GM you've made a transmission that can convert 850hp and torque to the road, why does it shake itself to death when going into V4 AFM engaged (lug the motor) mode?"

I Think that is called dealer pushback,
which is why owners of Cadillacs, GMC trucks, Chevy Trucks, Corvettes, Camaros etc etc etc had to resort to this:

It ain't just Corvette owners whistling Dixie:

• 2015 Chevrolet Silverado
• 2016 Chevrolet Silverado
• 2017 Chevrolet Silverado
• 2018 Chevrolet Silverado
• 2019 Chevrolet Silverado

• 2017 Chevrolet Colorado
• 2018 Chevrolet Colorado
• 2019 Chevrolet Colorado

• 2015 Chevrolet Corvette
• 2016 Chevrolet Corvette
• 2017 Chevrolet Corvette
• 2018 Chevrolet Corvette
• 2019 Chevrolet Corvette

• 2016 Chevrolet Camaro
• 2017 Chevrolet Camaro
• 2018 Chevrolet Camaro
• 2019 Chevrolet Camaro

• 2015 Cadillac Escalade
• 2016 Cadillac Escalade
• 2017 Cadillac Escalade

• 2015 Escalade ESV
• 2016 Escalade ESV
• 2017 Escalade ESV

• 2016 Cadillac ATS
• 2017 Cadillac ATS
• 2018 Cadillac ATS
• 2019 Cadillac ATS

• 2016 Cadillac ATS-V
• 2017 Cadillac ATS-V
• 2018 Cadillac ATS-V
• 2019 Cadillac ATS-V

• 2016 Cadillac CTS
• 2017 Cadillac CTS
• 2018 Cadillac CTS
• 2019 Cadillac CTS

• 2016 Cadillac CT6
• 2017 Cadillac CT6
• 2018 Cadillac CT6
• 2019 Cadillac CT6

• 2016 Cadillac CTS-V
• 2017 Cadillac CTS-V
• 2018 Cadillac CTS-V
• 2019 Cadillac CTS-V

• 2015 GMC Sierra
• 2016 GMC Sierra
• 2017 GMC Sierra
• 2018 GMC Sierra
• 2019 GMC Sierra

• 2015 GMC Yukon
• 2016 GMC Yukon
• 2017 GMC Yukon
• 2018 GMC Yukon
• 2019 GMC Yukon

• 2015 GMC Yukon XL
• 2016 GMC Yukon XL
• 2017 GMC Yukon XL
• 2018 GMC Yukon XL
• 2019 GMC Yukon XL

• 2015 Yukon Denali
• 2016 Yukon Denali
• 2017 Yukon Denali

• 2015 Yukon Denali XL
• 2016 Yukon Denali XL
• 2017 Yukon Denali XL

• 2017 GMC Canyon
• 2018 GMC Canyon

What the range does: DISABLES AFM, STOPS the AFM collapsing valve lifters from collapsing and keeps them rigid, just like the normal valve lifters. Keeps the V8 motor a V8 motor. Just a few whiffs of smoke now, citing AFM lifter failures, But stay tuned, more miles more AFM valve lifters gonna fail. Smoke now, fires to start..

IF THE AFM IS PERFECT, WHY DID CHEVROLET REMOVE IT THEMSELVES FROM THE ZR1 MOTOR? RANGE and the Stingray, GS, and Z06: same as GM's ZR1 motor's preferred choice: V8 motor full time, all the time. I think I'll follow the General's thinking (and action) on this one. I can wish in one hand for a successful Class Action lawsuit outcome, and I can spit in the other. But after all is said and done, I 'spect all I will have is a bucket of warm spit.

7700 miles smooth as silk A8 tranny miles on two A8 C7's, WITH RANGE ON.

RANGE STAYS ON.

 

No, it's called not throwing parts at a problem as a wild *** guess or based of what the forum says. Same reason multiple people had TC's replaced only to have the issue come back.

With only 2,8xx ZR1 cars built, GM didn't care about the minuscule uptick in CAFE standards etc. It's likely the same reason the Corvette and Duramax trucks don't have auto-stop like the rest of the passenger cars, cross overs and other grocery getter models.

If the Range makes you sleep better at night than it's good for you and congrats. We've had several customers with Range devices come in with the shudder and get the fluid changed with the most current stuff. FWIW we obviously service a lot more than just Corvettes and a much higher number of those vehicles are equipped with the A8. Our shudder complaints are 10x on Corvettes than all the others combined, even though Corvettes are a much smaller number of vehicles serviced in total. More than 50% of the customers "complaining" about the shudder have "read it online" or walk in with the TSB number in hand.

Without the "snowball" effect of the forums the shudder "issue" would be drastically less well known and much less of a concern for the vast majority of those experiencing the "issue." I know it can be hard to not consume yourself with the regurgitated "truths" of this forum, but often you'll find more realistic solutions, statistics and less fluff when you're willing to listen to somebody in the industry. I don't work for GM, I run a GM dealership so customers are the only reason I have a job. If I lie to them or bullshit the truths then I eventually won't have a job. Do some searching on here and let me know if you think I have any reason to make stuff up. I think you'll find I'm often more truthful and expressive than what GM might even like.

If you're the litigious type and want to jump on board the class action lawsuit for an issue that at best is a minor annoyance, then go for it. I just wish people didn't always jump all the way to the nuclear conclusion of "let's sue them bastards" for something that I find slightly annoying in my life.

What do you think GM owes you for your supposed shudder concern that you've admittedly never experienced? A free oil change or a new car? Do you want to sue the power company if your power is out for a day? How about "getting even" with the grocery store for selling you some expired milk? It's all about the same level of inconvenience and GM is offering free transmission fluid changes for the duration of your power train warranty as long as the "issue" can be duplicated.

 

Lets not let GM off the hook completely.
4 years to come up with a new fluid!
How long will the lock up clutch last with the shudder?
How many people will run out on their warranty-especially Vette owners and
then find out that a revised trans fluid formula was available.

 

I have experienced the shudder even with the Range. I know there were others on this forum that had more shudder, with the Range and with the triple flush of the latest blue label fluid.If I recall, some had low mileage, others above 20K.

As far as class action lawsuits go, I am sure the lawyers will make (tens of) millions while us poor dumb slob owners will get a coupon good for $100 off our next GM purchase of a $100k car as a settlement. And that coupon will expire in 30 days...

 

There's no such thing as a perfect transmission and even the best engineered will still have some degree of failure.

 

^^^^^^^^^^THIS ^^^^^^^

look up Nissians CVT transmission failures, $8,000 transmisson replacement cost , nobody will touch it to rebuild . Daughters Altima with 61,000 easy miles bit the dust . Transmisson cost more than the car was worth ...found out that they extended the warranty to 120,000 miles by accident ..... She now has 100,000 on it and now she is worried , car is perfect looks great get fantastic gas milage but we know the trans is a ticking time bomb because they did nothing as far as a redesign ....
Dave

 

The issue for me isn't if the range device works or not. It isn't if the fluid is at fault and it isn't TC design or operation......it's how GM has handled the entire issue. I've been playing phone and email tag with three GM service advisers since mid August over my shudder. Two triple flushes. I added lubegard and it has helped quite a bit but the shudder is back.
When you are told by GM AND the dealer technician that a small amount of shudder is normal.....in a 60k plus vehicle,it's obvious they are playing a waiting game with warranty....
The original dealer will not work on my car any longer. My nearby dealer says he won't work on it either and that I should bring it to the original dealer?

It is what it is folks. I'll do a few drain and fills myself. The lubegard did make a significant difference and I will add it to any refill that I do.....

 

The irony for me is that a few years before I bought my 17 GS, I was shopping for a daily driver to replace my Tahoe. I thought the Nissan Pathfinder would work until I joined their forum and saw all the issues with shudder from the CVT transmission (that is where I first read the words "feels like driving over rumble strips"). I bought a Ford Escape for much less, and it runs fine. Then two months ago I got the shudder in the GS at 9K miles. Got the latest fluid change, all is fine for now, extended warranty coverage ratchets the stress level down a notch.

 

How about the RPM fluctuations? Is that not the TC? Mine varies 50-200 RPM at cruising speeds constantly unless I have the Range plugged in. So aggravating

 

That is normal but ... that rpm fluctuation is the pulsing of the lockup converter in AFM mode and that is what is causing the torque converter clutch to eat itself ....

As long as your lockup clutch is not completely trashed from going in and out of lockup mode in 4 cylinder mode the Range will work and keep the lockup converter from destroying itself as lockup converters have been around a long time and work perfect in V8 mode

But this AFM issue , at the risk of over simplification , the TCM uses different modes of "Lockup" slip when in 8 cylinder and 4 cylinder modes .

In 4 cylinder mode the constant pulsing of the lockup converter is more frequent allowing for more slip , it is this higher level of slip that is causing the damage to the converter

GM has a firmware update that tries to modify the 4 cylinder lockup programming . along with the fluid flush ...this their answer to the problem... which in some cases works and others it does not as in the case of Yellow2007

I am playing it on the safe side , I have not had any issues except for a brief encounter with the rumble strip vibration , it was at that point, before my converter clutch ate itself when I bought a Range device and I have not had any issues since

The fluid flush is a bandage...sure it works for some but I am betting that the rumble vibration will return as it has for many

Yellow2007 , I would demand to speak to a Zone Rep , they visit dealerships on a frequent basis . Be prepared to take the rep on a ride where you can duplicate the issue .
Also demand that the they log your ride with the PICO test as this will tell the rep if you truely have an issue with the trans or not ...

The reason why I say this is briefly I thought my vibration came back , almost the same but it was slightly different

Turns out I lost a wheel weight off of my rim and it was producing the same rumble strip vibration but it was at a different RPM level and my AFM was off .

If you have not had your tires "Road Force" balanced I would recommend that you have it done . I had one tire that was really out and it took Discount several tries to get it within spec . And wouldn't you know it , that was the rim that threw the weight off of it

After working on your car so many times , I am starting to believe that something else is causing your issue , everybody is to focused on the trans when in fact it could be a multitude of other rotating parts that can produce the same harmonic vibration .. get the wheels balanced and get the PICO test done .

Dave

 

RichieRich ZO6 you made me sad as I was sure you would reply to my post with some corp BS ....

Dave

 

Thank you Dave. A zone rep is most likely my only option at this point. I'm guessing I can look in the owners manual for numbers.....👍 👍

 

When milk costs over 60 thousand dollars a gallon yes......I would want to "get even"