OK.... I have a perfectly functional A8 in the low mile (8K current, built Aug 2014) 2015 Z51 I just bought. Drove it about 1,400 miles "bringing it home" and not a sign of any of the reported issues.

I am usually a "if it ain't broke, don't fix it" guy but I have a serious question about any PROVEN preventive measures (triple flush, etc.) that will eliminate or lessen the odds of failure down the road..... do any exist!?

I have read every thread I could find on the subject and it seems the problem is elusive at best and also random. Any rational and concrete suggestions are appreciated....BTW I am still in factory warranty and will put a GMEPP into place in Sept. so it will cover future problems with the A8, that is not my issue/question.... it is about prevention....smile... thanks, LK

 

I don't think any method of prevention is 100% proven just yet but a lot of people speculate that if you drive it in manual mode most of the time, and keep it out of V4 mode, that will help the A8 last longer.

 

I went with a Range since I already have a 4 cylinder in my truck when I want that kind of excitement. Easier than manual mode all the time.

 

Never, ever let it go into V4 mode! Place in "M" and use the paddles to shift "manually" or install a Range Technology device to defeat AFM.

Personally, I drive my Callaway in Manual always and I love it. All the benefits of having an M7 without the annoyance of having to deal with a clutch. You don't even have to downshift as it does so automatically.

The A8 is an engineering wonder, but it has gotten a "bad rap" because of the ill-effects of the goofy AFM system that GM decided to incorporate because of CAFE requirements.

 

I have a 16 with less than 900 miles on it. Still cannot understand the "random" thing with the TC issue. Random, WTF?

 

OK.... found the Range Technology on Amazon for $190 with three TERRIBLE reviews..... looked on vendor site and they have a $10 off with free shipping offer until Labor Day... SUMMER2017 discount code.... same basic cost...


My question is.... what is the experience of C7 owners with this device and how does it work for YOU..... anyone out there with good or bad reports on this.

Claims to do more than just avoid AFM mode... also saw "frequent S/W updates" and warning to buy directly from vendor vs.....say, Amazon to ensure current and warranted product.

Question, do any of the modes (e.g. Sport") stop tranny from slipping into v4 mode without an OBD contraption ...... battery drain, etc.... thanks,

LK

 

Which model did you get..... see vendor site.... two to choose from...LK

https://rangetechnology.com/

 

following

 

Only solution I see is to disable AFM, via staying in manual mode or something else.

 

I also have a 15 Z51 built in July 2014. My advise is to drive it and enjoy. Whatever is going to happen will happen and there is really nothing you can do about it. I have no problems with mine and never worry about things I have no control over.

 

I have a 2016 Z06 and a Range module V8.1 that I haven't sent in for the update yet, I turn it off (via switched OBD II cable) when the engine is off and turn it on after starting which avoids the CEL and "limp" mode due to an intermittent loss of communications between the engine and transmission that occurs randomly BUT only at startup. With the module turned on after starting (at least for 2016 and earlier) it will not set any codes during operation and works flawlessly in keeping V4 mode off. The current Range module apparently works perfectly for 2015 and 2016 vehicles and will NOT set a CEL at startup but should still be turned off when the car won't be driven for several days in order to avoid battery drain.

I have thought about the triple flush also even though my transmission has been flawless and my thought is the transmission is running the fluid that it was originally designed to use so I am going to leave it alone and stay out of V4 mode. The newer fluid is meant to combat the problems that occur because of torque converter clutch wear and I expect it does this via the use of a different (or higher concentration of) friction modifier. Whether this different composition fluid will have negative impacts on the other clutches will only be known over time. In addition to the lockup converter clutch which is the one causing the shudder issue there are three rotating clutches and two brake clutches used with the 4 planetary gear sets to provide the 8 forward and 1 reverse ranges. These clutch packs are far more complex and sophisticated than the relatively simple lockup clutch in the converter which only serves to increase fuel economy by removing torque converter slippage during steady state cruising or light acceleration. The new fluid is probably fine for these other clutch packs but I feel no need to experiment since my lockup clutch won't be getting beaten up by V4 mode operation.

 

I got my Range AFM Disabler on 7/20/17 (two day delivery from Range Technology with SUMMER2017 discount) for my 2016 with 14,500 trouble free miles on the A8. Wanted it mainly as a "preventative measure" based on all the problems some have reported arising from V4 TC slip operation. A major side benefit for me is that the car is much more "driveable" in V8, that is it is much easier to maintain a desired MPH in the hilly countryside around here than when operating in V8-V4-V8 modes (which transitioned seamlessly for me by the way).

In the almost two weeks/300 miles and many short DD trips, I have only experienced the CEL problem twice. Once, after the car sat for a day without being started, the light came on on initial start. The other time, I manually downshifted, immediately realized I was down a gear from where I wanted to be (the tranny had already done an auto downshift) and upshifted to the gear I wanted, probably before the transmission finished the commanded downshift.

Both times all I had to do is turn off the Range unit (I have it on a switched OBD cable) restart the car, then turn the Range back on. When turned on (or plugged in) after vehicle start, the Range clears all CEL codes as part of its boot up protocol.

The other issue reported with this unit is the potential for battery drain if the car is not driven/not on battery tender for several days. Since I daily drive the car, I don't turn the unit off daily like many do and have had absolutely no battery problem. However, I do plan to eventually wire power to a switched source as document in other threads on the forum here, so if I go away for a few days, I do not have to remember to switch the unit off. I will do this while maintaining the "switched" operation so I can still shut the unit off when cruising the interstate to get the great mileage that V4 has provided me so far.

 

After having the triple flush done about 1300 miles ago. I will continue to drive mine in manuel mode until GM comes up with a resolution or I trade the car.
The shift from 1st to 2nd, under rapid acceleration, when you're turning takes a little technique, but you get used to it after a while.

 

Be careful because cruising the interstate in V4 mode is potentially where the most damage to the torque converter clutch is occurring. Some of the GM documents imply the modulation of the torque converter clutch is not used when the engine is exceeding 1,600 RPM but I have not seen anything specifically stating whether this is true of the Corvette. If it is true then running in V4 mode at a cruising speed that exceeds 1,600 engine RPM should be OK. Hopefully someone who is currently experiencing severe shudder in V4 mode will experiment to see whether the shudder disappears in V4 mode at engine revs exceeding 1,600. The problem is that with a 2.41 rear axle ratio (Z06 or C7 without Z51 package) this will occur around 80 MPH which may be faster than some wish to cruise on the interstate.

 

Just curious--If the car is out of warranty what cost would there be to replace the TC.

 

No one can give you PROVEN anything around here, it's just a forum, not a court or laboratory.

Anyway, I have reasonably high confidence (but not proof) the eliminating AFM will extend the life of your TC clutches. You can do that with a tune (possible warranty void) or a Range AFM module (possible CEL and dead battery).

 

Since it's uncertain if even GM knows exactly what is causing the problems and how to prevent them, my plan is to:
Buy extended warranty from Ken Fichtner within the first 10k miles/year, enjoy the car, and let them fix anything that goes wrong. That's what we did with our previous three Corvettes, and (unfortunately) we made money on the warranty with each of them.

I don't think GM has it in their DNA to produce a Corvette with long term reliability. Some people get lucky, but we haven't and I'm not expecting anything different this time.

 

Lenny, I've looked at those on Amazon, and even some on Ebay that are sold a little cheaper. But, I'm not sure what version they are selling. So, I'm going to buy mine straight from Range to get the latest, and greatest. Plus, from reading tons of threads here it is obvious Range has great customer service, and going through another seller makes me wonder if one could get that same level of support. Also as NSC5 says below I will buy a OBD switched extension so it can be turned off when the car is no being driven.



[B]
[QUOTE=NSC5;[/B]1595265643]I have a 2016 Z06 and a Range module V8.1 that I haven't sent in for the update yet, I turn it off (via switched OBD II cable) when the engine is off and turn it on after starting which avoids the CEL and "limp" mode due to an intermittent loss of communications between the engine and transmission that occurs randomly BUT only at startup. With the module turned on after starting (at least for 2016 and earlier) it will not set any codes during operation and works flawlessly in keeping V4 mode off. The current Range module apparently works perfectly for 2015 and 2016 vehicles and will NOT set a CEL at startup but should still be turned off when the car won't be driven for several days in order to avoid battery drain.

[/QUOTE

NSC5, after all of your research along with Thunder22's I'm going with the switched OBD extension. Even though Range may have the CEL issues at bay with their new version I don't think I'll risk it just for my peace of mind.

Jim

 

Another vote for: start the car, let the idle settle, reach down and flip the switched cable to the Range on, drive, park, turn off the car, reach down and turn the Range off. No CEL's in my couple of months, couple thousand miles. Only thing is I haven't found a good solution to the location of the switched cable. I like to see the Range's lights on and be able to easily reach the switch. Seems the only way I can do both is to let the Range sit on the floor and the cable drape straight down from the OBD.

 

I ran the cable from the OBD-II port to the right side of the torque tube tunnel. The switch is mounted high where it is easily reachable but nearly out of sight and the port with the Range module is a little lower with the Range pointed down so that I can see the lights when I look down but they aren't shining out/up at me which can be annoying.