2017 Canyon V6 transmission issue

CanyonHypermiler · February 26, 2018

Wondering if anyone else has noticed anything wrong with their 8 speed transmissions.. Over the last 100 miles or so I have noticed what I can only describe as a cavitation coming from my transmission. It's usually occurs when travelling in the top gear (8th) and under moderate throttle (picking up speed). I can feel a vibration in the gas pedal, seat, and steering wheel. I thought it might just be bad gas and the engine was hesitating a little, but that's not it. I filled up with premium on the last tank and still having the same issue. I use the word cavitation because it feels like the vibration you'd get in a boat when the prop hits an air pocket.. like a really fast vibration. It's also similar to an engine bogging in a manual transmission when you're in too high a gear with too little speed.

Anyone else noticed their transmission making any similar vibrations? I've scheduled a service visit. Truck only has 16,000 miles so I hope there is nothing catastrophic going on. Thanks for your input.

Rick D. · April 17, 2018

On 2/26/2018 at 6:44 AM, CanyonHypermiler said:

Wondering if anyone else has noticed anything wrong with their 8 speed transmissions.. Over the last 100 miles or so I have noticed what I can only describe as a cavitation coming from my transmission. It's usually occurs when travelling in the top gear (8th) and under moderate throttle (picking up speed). I can feel a vibration in the gas pedal, seat, and steering wheel. I thought it might just be bad gas and the engine was hesitating a little, but that's not it. I filled up with premium on the last tank and still having the same issue. I use the word cavitation because it feels like the vibration you'd get in a boat when the prop hits an air pocket.. like a really fast vibration. It's also similar to an engine bogging in a manual transmission when you're in too high a gear with too little speed.

Anyone else noticed their transmission making any similar vibrations? I've scheduled a service visit. Truck only has 16,000 miles so I hope there is nothing catastrophic going on. Thanks for your input.

I have a 2017 Canyon with 2,500 miles. Yes, I do not it stumbling a lot. I had a 2015 with the six speed and traded it due to the same problem. After re-flashing the trans ECM, still no improvement. Now, the 2017 is going in for diagnosis. It seems the software is the culprit. I hope that they have a fix.

CanyonHypermiler · April 17, 2018

Hi Rick, an update to the transmission issue... I took it in for service and they did not find the problem. I took the truck out for a drive with the Service Manager and, of course, the transmission did NOT act up with him with me. The issue continued to get worse over the next 500 miles, so I took it in again to have it checked along with an oil change. They called me and said they had found a Technical Service Bulletin for the exact same issue I am having. The TSB describes the issue as this.. "Vibration felt coming from transmission when using light throttle going uphill, or light throttle accelerating in higher gears. Also hesitation when accelerating away from a stop when gears are about to change.". The TSB recommended a full transmission fluid flush and the truck be driven at least 200 miles before the issue is reported again for service.

Currently I have driven the truck over 200 miles and do not notice any vibration and no hesitation in the transmission. I hope the issue has been fixed, but I'm leary that a simple trans flush is the long-term solution. Time will tell I guess.

Thanks for the reply Rick.

S Moore · April 17, 2018

5 hours ago, CanyonHypermiler said:

Hi Rick, an update to the transmission issue... I took it in for service and they did not find the problem. I took the truck out for a drive with the Service Manager and, of course, the transmission did NOT act up with him with me. The issue continued to get worse over the next 500 miles, so I took it in again to have it checked along with an oil change. They called me and said they had found a Technical Service Bulletin for the exact same issue I am having. The TSB describes the issue as this.. "Vibration felt coming from transmission when using light throttle going uphill, or light throttle accelerating in higher gears. Also hesitation when accelerating away from a stop when gears are about to change.". The TSB recommended a full transmission fluid flush and the truck be driven at least 200 miles before the issue is reported again for service.

Currently I have driven the truck over 200 miles and do not notice any vibration and no hesitation in the transmission. I hope the issue has been fixed, but I'm leary that a simple trans flush is the long-term solution. Time will tell I guess.

Thanks for the reply Rick.

I wonder if this would fix the same issue on my 2016?

Googled · May 7, 2018

Hi CanyonHypermiler, I just bought a new 2018 Canyon with the 8 speed transmission in it to replace a 2016 model with a 6 speed tranny that GM would not fix. This one started having the problem that you describe within 3 days of purchasing it. The dealer checked it and said it was the torque convertor and it needed to be replaced. When I took it in for that repair, they told me that instead of replacing the torque convertor, they were told by GM that the transmission fluid needed to be replaced first. I was very skeptical and didn't believe this would solve the problem but I had to let them try before I took any further actions. When I got the truck back, I was pleasantly surprised that the truck was and has been running "as designed" only better. I do not know if this will continue but hope it will. (Through some other forum, I read that GM used the wrong transmission fluid in the newer trucks)? Good Luck with yours.

Edited May 7, 2018 by rpett
Sent to Rick instead of CanyonHypermiler

rustbukt307 · June 16, 2018

Just got a 2018 myself with the 3.6/8-spd and so far no problems. A friend of mine with a 2016 Camaro SS is having this issue with her 8-spd though. I read some entire post from a GM engineer saying the fix was repeated trans fluid flushes (about three of them) because the issue had to do with "the quality of the friction modifier in the fluid collected from customer's cars." The common complaint being a "shudder" during torque converter operation.

CanyonHypermiler · July 16, 2018

On ‎5‎/‎7‎/‎2018 at 7:41 PM, rpett said:

Hi CanyonHypermiler, I just bought a new 2018 Canyon with the 8 speed transmission in it to replace a 2016 model with a 6 speed tranny that GM would not fix. This one started having the problem that you describe within 3 days of purchasing it. The dealer checked it and said it was the torque convertor and it needed to be replaced. When I took it in for that repair, they told me that instead of replacing the torque convertor, they were told by GM that the transmission fluid needed to be replaced first. I was very skeptical and didn't believe this would solve the problem but I had to let them try before I took any further actions. When I got the truck back, I was pleasantly surprised that the truck was and has been running "as designed" only better. I do not know if this will continue but hope it will. (Through some other forum, I read that GM used the wrong transmission fluid in the newer trucks)? Good Luck with yours.

I ran into the same issue. They found a Technical Service Bulletin that addressed the EXACT issue I was having... vibration from the transmission under load on the torque converter. They recommended a complete trans flush. I can say that after the flush, the transmission was smooth as glass... like new again. After a few thousand miles, the same issue is back, although not as severe. I am not getting the hard vibration that I was getting before, but a softer vibration. The transmission is still hesitating a LOT before upshifting to a lower gear going up a hill though. If I get to a hill, and feed in more gas, then more gas, then MORE gas the transmission hesitates before finally upshifting to the next gear or even 2 gears lower to handle the hill. I'm taking the truck back for an oil change/tire rotation in another 500 miles. I"ll address the issue again and report back. It looks like from other posts that GM will probably recommend another full trans flush again. As a side note, I'm pretty happy with the truck, but disappointed with the transmission aside from the issues i'm having. The transmission to me is LAZY.. slow to shift, never seems to be in the right gear, and it hurries to get to the highest gear for better fuel economy. Thanks for the replies!

CanyonHypermiler · July 16, 2018

On ‎6‎/‎16‎/‎2018 at 9:54 AM, rustbukt307 said:

Just got a 2018 myself with the 3.6/8-spd and so far no problems. A friend of mine with a 2016 Camaro SS is having this issue with her 8-spd though. I read some entire post from a GM engineer saying the fix was repeated trans fluid flushes (about three of them) because the issue had to do with "the quality of the friction modifier in the fluid collected from customer's cars." The common complaint being a "shudder" during torque converter operation.

Rustbukt, see my reply to 'rpett'. Same issue. I"ll have more to report back after my next service in a month or so. Hopefully the problem gets better with the multiple trans flushes.

CanyonHypermiler · July 17, 2018

On 5/7/2018 at 7:41 PM, rpett said:

Hi CanyonHypermiler, I just bought a new 2018 Canyon with the 8 speed transmission in it to replace a 2016 model with a 6 speed tranny that GM would not fix. This one started having the problem that you describe within 3 days of purchasing it. The dealer checked it and said it was the torque convertor and it needed to be replaced. When I took it in for that repair, they told me that instead of replacing the torque convertor, they were told by GM that the transmission fluid needed to be replaced first. I was very skeptical and didn't believe this would solve the problem but I had to let them try before I took any further actions. When I got the truck back, I was pleasantly surprised that the truck was and has been running "as designed" only better. I do not know if this will continue but hope it will. (Through some other forum, I read that GM used the wrong transmission fluid in the newer trucks)? Good Luck with yours.

Rpett, after the first transmission flush the truck performed great.. smooth shifting, quick shifting, no issues. After about 1000 miles I noticed slight hesitation and the problem has been creeping back in and getting worse. Truck will be back in the dealer in the next month. I have a local resource that works for a GM dealer close to my home. I emailed him my issues and he's checking with his GM Master mechanic to find out what the 'long term' plan will be for all these trucks with transmission issues. Like you, I"m skeptical that a trans flush will alleviate the problem. I"m also skeptical that there has not been any damage caused to my transmission. Some of the vibrations have been bad enough to rattle the change I keep in the dash tray. I"ll post back after my next visit.

CanyonHypermiler · July 17, 2018

On 6/16/2018 at 9:54 AM, rustbukt307 said:

Just got a 2018 myself with the 3.6/8-spd and so far no problems. A friend of mine with a 2016 Camaro SS is having this issue with her 8-spd though. I read some entire post from a GM engineer saying the fix was repeated trans fluid flushes (about three of them) because the issue had to do with "the quality of the friction modifier in the fluid collected from customer's cars." The common complaint being a "shudder" during torque converter operation.

I know that the same 8 spd transmissions are used across multiple platforms at GM. I"m sure the 8 spd in the Camaro is programmed to be more sporty than in a truck. I haven't done any research on the Camaro transmission. I"m keeping my fingers crossed that after this next visit (if they decide to flush the transmission...) the problem will go away. Thanks for the reply.

EDL · July 17, 2018

My new 2018 Silverado with the 8-speed acts similar. It doesn't rattle spare change or anything, but there is definitely vibration in the drive train that varies depending on throttle position and load, and even just cruising at a steady speed (but I also think the cruising vibration is due to a different issue). It can be felt in the steering wheel, pedals and just generally throughout the truck. I have no issues with the transmission downshifting to go up hills, but I also have the 6.2L v-8 and the torque is sufficient to not need to downshift so much unless under heavier throttle. After driving it for almost a month now, I've "learned" the throttle and have no issues getting it to downshift when I want it to. I just can't tell if it is an issue with the transmission, the torque converter or the perhaps something in the transfer case, the CV joints, differential, drive shaft or a combinations of any or all of these as the steering while has vibration no matter what speed or throttle (at least more than I think it should have).

The transmission definitely has the engine start surging. Within a second or two of starting the truck, the transmission thunks and the truck will actually lurch a little. This is a known issue and GM bulletins say to not attempt any repairs. Apparently tranny fluid doesn't drain down completely after shutting off the truck which causes this. I've found that letting the truck idle for about 20-30 seconds after putting it in park alleviates the issue.

One other issue is that the transmission has a tendency to downshift hard (causes a thunk) when slowing down to a stop and it shifts from 2nd to 1st. Doesn't always do it, but does do it frequently. I hope a fluid exchange will fix this as well.

I also think the drive shaft is not true and out of balance to some degree as driving at a steady speed the truck just vibrates and is more noticeable at higher (i.e. highway) speeds. It's not the massive "chevy shake" that some have, but it's a noticeable less than expected smoothness overall. It's enough to cause a slight, deep rumble in the cabin too. I'm pretty sure the shaft needs some work as I've had this issue on other trucks, so I know what it feels like. I'll happily pay the local drive line shop the $90 they want to true and balance it. Just to rule it out, I'll have them road force balance the tires too, but it's not the same feel as out of balance tires.

I have to take it in to get one of my fobs properly programmed (the #1 fob won't work with the memory settings), so I'll see if they'll do the fluid exchange on the tranny while there and see what, if any change this makes to any of the vibrations and thunking. I just hate fighting with dealerships on this kind of crap because they always try to find ways to say nothing is wrong or they always want to do a bunch of other stuff that everyone knows isn't going to fix anything. Then there is the hassle of not having transportation or having to juggle around getting to and from work with the wife an so on.

Edited July 17, 2018 by EDL

Z45 · July 17, 2018

The GM branded AC Delco Dexron HP is the problem, poor quality oem fluid that does not hold up. Some dealers may still have it in stock so it may still get put in some vehicles even though its discontinued. They won't lose money.

This has been out since 2016...................

Engineering notes:
PART NO 19331925. FLUID. WILL BE REPLACED BY FLUID. PART NO 19353429. PLEASE REFER TO PARTS WORKBENCH FOR LATEST PART ORDERING INFORMATION AND AVAILABILITY.

19353429 - MOBIL 1 SYNTHETIC LV ATF HP TRANSMISSION FLUID - 1 QUART CONTAINER

GM Part No.: 19331925

Fluid,Automatic Transmission Synth Lv Dexron Hp Acdelco 12X1Qt

Part Description	FLUID,A/TRANS 32.0 OZ
Other Name	Standard Parts
Manufacturer	GM. This genuine GM part is guaranteed by GM's factory warranty.
Manufacturer's Notes	This part is discontinued. It is no longer available for purchase.

Edited July 17, 2018 by elcamino

Northman · July 17, 2018

1 hour ago, elcamino said:

The GM branded AC Delco Dexron HP is the problem, poor quality oem fluid that does not hold up. Some dealers may still have it in stock so it may still get put in some vehicles even though its discontinued. They won't lose money.

This has been out since 2016...................

Engineering notes:
PART NO 19331925. FLUID. WILL BE REPLACED BY FLUID. PART NO 19353429. PLEASE REFER TO PARTS WORKBENCH FOR LATEST PART ORDERING INFORMATION AND AVAILABILITY.

19353429 - MOBIL 1 SYNTHETIC LV ATF HP TRANSMISSION FLUID - 1 QUART CONTAINER

GM Part No.: 19331925

Fluid,Automatic Transmission Synth Lv Dexron Hp Acdelco 12X1Qt

Part Description FLUID,A/TRANS 32.0 OZ
Other Name Standard Parts
Manufacturer GM. This genuine GM part is guaranteed by GM's factory warranty.
Manufacturer's Notes
This part is discontinued. It is no longer available for purchase.

Had a former retired employee stop by while her new equinox was in the shop getting the transmission fluid changed due to a recall. She said she knew of three others in town being recalled for the same reason. Must be pretty widespread.

newdude · July 17, 2018

We've done 3 converters here on Colorados. They all got the triple flush first, only to get converters. None of the 3 have been back since.

20 minutes ago, Northman said:

Had a former retired employee stop by while her new equinox was in the shop getting the transmission fluid changed due to a recall. She said she knew of three others in town being recalled for the same reason. Must be pretty widespread.

Equinox uses the 9T50 transmission and use Dexron 6. No recalls either on the Equinox for the transmission. There is however, a bulletin on the 9T transmissions for valve body plate machining errors that can cause loss of some or all gears/forward movement. We had a couple of those, they got new spacer plates and a reprogram.

Z45 · July 17, 2018

Note ----- Recalls apply only to items that could affect vehicle occupancy safety. Items listed under separate manufacturer technical service bulletins are not always covered by warranty.

Edited July 17, 2018 by elcamino

Not1lost · September 8, 2018

My 2017 Canyon v6 SLE 4x4 doing the same vibration, shudder thing and getting worse and worse,, only 14000 miles. Didn’t do this until after about 12000. Trans. Heats up to as high as 150º sometimes! What I am concerned about is how much damage has this already done to the longevity of the transmission? Like going out right after warranty??? No matter how many flushes and converters you do. I am afraid of the truck now even though I do love everything else about it. Sad to say but I think the best thing is to get rid of it by haveing them take it back for another truck with a different transmission. I’m retired and I will not be able to pay for a new transmission 5-10 years down the road. Any advice would be appreciated; thanks.