12-05-2019, 05:20 PM | #1 |
Drives: 2018 Camaro V6/RS Join Date: Nov 2018
Location: MI
Posts: 1,596
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AFM V4 mode
So I got to thinking, and was hoping someone might have an answer to this. When the car transitions into V4 mode and has the obvious throb or shudder type feeling, is that causing accelerated wear on the trans and or torque converter? I had the latest fluid/flush done (and it seems okay right now) but the constant transitioning in and out of V4 mode feels like a mild form of shuddering. If disabling it doesn't help prolong the life of the torque converter and whatnot then I probably wouldn't even bother, but if it helps it would be more than worth it in my opinion
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12-05-2019, 06:19 PM | #2 |
Drives: 2019 2SS Join Date: Mar 2019
Location: WA
Posts: 67
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My '19 does the shift in and out seamlessly without any hint except the indicator on the dash.
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12-05-2019, 06:26 PM | #3 |
Drives: 2018 Camaro V6/RS Join Date: Nov 2018
Location: MI
Posts: 1,596
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12-05-2019, 06:59 PM | #4 |
Drives: 2017 Camaro SS Fifty Join Date: Oct 2016
Location: Port St Lucie, Florida
Posts: 966
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I also can't feel the transition to V4 mode but the theory is that it causes the torque converter issue. I have the Range Unit which prevents the AFM V4 from engaging. I unplugged it to see what would happen and the shutter returned within 1000 miles. I have 9500 miles on My 2017 SS and have had the flush done twice. I have extended warranty so not really worried about weather or not it returns after the last flush with Mobil 1 syn. Mine gets 2 to 3 mpg less with the Range unit plugged in. I would rather it fail and GM replaces the TC than wait till after my extended warranty runs out and I would have to pay for it.
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12-05-2019, 07:19 PM | #5 | |
Drives: 2018 Camaro V6/RS Join Date: Nov 2018
Location: MI
Posts: 1,596
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Quote:
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12-05-2019, 09:47 PM | #6 |
Drives: 2020 1SS 1LE M6 was 2018 V6 RS A8 Join Date: May 2018
Location: Minnesota
Posts: 59
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I have a little over 15K miles on my 2018 V6 RS and have never felt anything when switching from V6 to V4 mode. I'm hoping that it stays that way. We'll see.
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12-05-2019, 10:03 PM | #7 |
I don't think that anyone can prove with 100% certainty that V4 directly harms the TC, but it most definitely locks and unlocks more often when V4 is enabled, and shifts much more often as well.
That frequent churn while attempting to hold speed and power as you drive down the road cannot be good for any part of the drive train long-term. But yes, the shudder can be a very real and serious thing. I too now have a Range and my car has a far more solid feel. It cost me about 1.5mpg overall but I do mostly highway driving. I tried removing it for a couple of days and could quite easily easily feel all the dithering in and out of lockup and gears and found it extremely annoying. So I put it back in where it remains. I changed the fluid myself recently even though I did not have the TC shudder (yet). I want to take no chances. It really isn't difficult to do by the way and I was able to change out around 8 full quarts easily. So although not as good as an actual flush, that wasn't bad either. FWIW.......
__________________
Gen6 Camaro LT (my daily driver), Cruze ECO (grocery getter), Chevy SS Pickup (wife's daily driver), Honda Shadow, Honda CBX
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12-06-2019, 06:23 AM | #8 |
Drives: 2017 50th Anniversary SS Join Date: Mar 2016
Location: BG, Ohio
Posts: 154
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34000 on my 2017 and I have never felt a thing switching from 8 to 4 or back and never had A8 shudder either. I do feel a transition when switching drive modes at speed Tour to Sport or Track, Sport to Track but not Track to Sport or Tour, or Sport to Tour.
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12-06-2019, 07:30 AM | #9 | |
Drives: 2018 Camaro V6/RS Join Date: Nov 2018
Location: MI
Posts: 1,596
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Quote:
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12-06-2019, 07:58 AM | #10 | |
Drives: 2017 Camaro SS Fifty Join Date: Oct 2016
Location: Port St Lucie, Florida
Posts: 966
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Quote:
Doesn't that mix the new Mobil 1 synthetic with the old GM non-synthetic? |
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12-06-2019, 08:03 AM | #11 |
Thank you Al Oppenheiser!
Drives: Red Hot A10 ZL1 Convertible Join Date: Jun 2017
Location: Sarasota, FL
Posts: 4,966
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Yes some NVH during transitions into and out of V4 mode with the AFM are inevitable. To minimize this NVH during AFM engagement/disengagement, GM designed and implemented the continuous slip in the clutches of the torque converter. This slip minimizes the torque transients while still allowing power transmission, maximizing the fuel economy gains of the AFM system while minimizing the NVH effects pointed out by HCI2000SS above.
To allow the clutches to continuously slip, a new trans fluid had to be made with special friction modifiers. Those friction modifiers degrade in the presence of moisture. Once degraded, the fluid can cause a stick-slip condition inside the torque converter clutches, causing the shudder problem we all know. If the bad fluid is replaced with the upgraded "2019 fluid", the problem goes away and I have yet to see a single report that it returns. But if left unattended, the shudder will eventually cause hot spots to form and permanent damage results requiring torque converter replacement. I have yet to see a single issue of AFM-caused torque converter failure that was NOT directly related to the bad fluid. See also additional info on this in the "ASK AL" section here, including the original TSB (which IIRC has been revised): https://www.camaro6.com/forums/showthread.php?t=527133 |
12-06-2019, 08:36 AM | #12 |
Drives: Chevy Camaro Join Date: Jul 2019
Location: Dallas
Posts: 420
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I have a 19 SS with 6300 miles, I feel it during the transition.
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12-06-2019, 08:42 AM | #13 |
Drives: 2016 Camaro 1LT Join Date: Jan 2016
Location: California
Posts: 3,491
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My V6 is perfectly fine with the shift to v4 mode.
though, I also have a tune that increases the transmission line pressure over stock so maybe that helps. Though, there seems to be significantly less chatter about problems with any kind of shudder during transition with even the stock engine. sounds to me like you guys with the v8 should have gotten a v6 |
12-06-2019, 08:44 AM | #14 |
Drives: 2018 Camaro V6/RS Join Date: Nov 2018
Location: MI
Posts: 1,596
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Thanks for the replies! To sum it up, it sounds like disabling the AFM could only help extend the life of the torque converter correct? I understand there is really no way to comparitevly measure this, but it does sound like it produces somewhat excessive wear on the torque converter at some level
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