2017 Canyon 8 Speed Absolutely Horrible

HunterSr · June 24, 2019

I purchased a brand new 2017 Canyon 2WD 3.6L 8 speed. It now has about 10,000 miles on it. It hardly ever goes on the highway. Last week I drove from Texas to California and back. The shudder/vibrate/surging on inclines was so bad I had to put it in 7th gear to drive home (it still had some shudder at times). I called my dealer yesterday and they said they are aware of the issue so tomorrow they will reprogram it and flush and replace the transmission fluid with a new/different type of fluid. Hopefully that'll fix it. I'll let everybody know how it goes.

MaverickZ71 · June 26, 2019

New transmissions are not necessarily performing as designed, but rather are performing as programmed.

What was the old GM Hydramatic division has built some of the world's best automatic transmissions since the 1950's. But the final powertrain calibration is done totally in the name of fuel economy. To hell with daily drivability, let's see if we can eek out another fraction of a mile per gallon. It doesn't make a damn if it's a 6-speed, 8-speed, or the new 10-speed (the transmission GM developed with Ford, by the way, it shifts better in Fords), they program the software to force it to upshift to top gear and lock the torque converter as soon as possible. To get it to downshift, you have to almost floor it and count to 3, at which point it slams a downshift and revs to 4K+ on the tach, which more often than not startles the driver and causes them to lift on the throttle, so it immediately shifts into top gear and starts the frustrating endless loop all over again. It is maddening, especially when a good aftermarket tuner like Blackbear can very so easily make a great improvement in drivability by just installing their tune.

Edited June 26, 2019 by MaverickZ71

HunterSr · July 8, 2019

Update to my post on June 24th regarding the terrible performance of my 10,000 mile 2017 Canyon 3.6L 8 speed shudder/shake/vibrate issue. Under warranty the dealer replaced the trans fluid with a new revised type/brand of fluid. They said they also did some reprogramming. WOW, what a change. The truck runs and shifts great now. It's like a totally different (much better) truck. Lots more power, quicker downshifts, no shudder or vibrating. It runs and shifts perfectly.

According to the dealer repair invoice they:

Performed DOC # 5181942 Shudder During Light Throttle Acceleration

Perform Diagnostic Testing and Fluid Exchange

Labor OP Code 8480818 1.4

Part Number Description Qty.

19417577 Fluid 20

Doug_Scott · July 8, 2019

Have to wonder where they manage to put 20 quarts (5 gallons) of fluid inside a transmission case that is full of metal parts with no room to even slip your hand inside. Even going back to the old days you didn't put 5 gallons in the transmission. I don't recall ever putting 16 quarts in a 727 or 904 transmission. I don't recall ever needing help carrying the required number of quarts of ATF, along with gasket and seal package, and even with clutch discs and steels, so it couldn't have been more than 7 or 8 quarts.

After reading far more than I wanted to, it seems that GM is trying some backward technology. They are trying to make the torque converter lock-up slip on purpose. Had they just called me I would have told them it won't be as simple as that. I could have regaled them with tales of complete dash assemblies jumping up and down 12 inches as the torque converter attempted to lock up indecisively. Have to wonder if Chrysler is having any issues with their automatics in the Demons and HellCats.

Ibmikey · July 9, 2019

Yes Doug, GM is remiss in not calling you for technical correction of their transmission woes...better yet why don’t you call them they will be anxiously waiting. I wish someone would help them out before next week when they install an eight speed in my new build. This will be my second Denali with the eight speed, the 2017 ran like a top rarely letting me know it was shifting. I read here that others have had different experiences, hopefully the flush will correct any difficulties they may have encountered. GM has built hundreds of thousands of the eight speed I would like to know what portion of those required maintenance, mine surely did not and I know of several other folks who are quite happy with the transmission.

Canyon Conundrum · October 8, 2019

Had updated fluid flush done in March 2019 Was good for a while. Fish bite / chuggle slowly came back. Just like the 3 "repairs"prior. Then it morphed into a full shudder. Which I am sure it will do shortly.Torque convertor was replaced,fluid flush(old fluid) and a update installed. I had a Field Service Engineer take it for a ride last week. He said "transmission performed as designed" If that's so then why did GM try to fix it 4 times? When I took the vehicle on a test drive if the transmission had "performed as designed" with the shudder evident I would not have bought it! I have opened a Better Business Bureau case hopefully for a buy back.This has been going on for over a year now.This is the worst new vehicle buying experience I have ever had. Doubtful I will ever buy a new vehicle again. At least not a GM product. If I bought a used vehicle without a warranty and I had transmission issues I could take it to a reliable transmission shop and the issue would be fixed.I have a new vehicle with a warranty with a transmission issue and GM cant fix it!

Old School 2u · January 26, 2020

Looks like nothing has changed for 2020 models.

One of my local dealerships recently received 3 of the new 2020 Canyons. I was excited to purchase one, thinking by 2020 they would have taken care of the 8 speed transmission issue. Boy, was I wrong! I took the SLT for a test drive and within 2 miles started having a "rumble strip" vibration as it shifted from 2nd to 3rd and 3rd to 4th etc. I stopped and started at least four times letting it run through the gears, under what I would consider normal acceleration, with the same results each time. I took it back to the dealer and informed them of the issue. The sales manager said he knew exactly what I was referring too and it needed the trans fluid flushed. He told me to go home and come back in three hours and it would be taken care of.... "guaranteed!"

About an hour later, my salesman called and said they were not going to do the flush on the truck. He said the service and sales manager drove both the one I had driven and the other two on the lot and they all have the exact same shudder. They said "this is normal for this vehicle" and nothing more could be done to remedy the issue.

I'm very disappointed in GM and the fact that they refuse to properly address this issue. I have been a GM fan my whole life. However, I am so thankful this issue showed itself during the test drive and not after I made the purchase........ I won't be buying a Canyon anytime soon!

divein · February 10, 2020

I'm looking to buy a used Colorado/Canyon but as of now planning to stick with 2016 or 2015 so will have the 6 speed tranny. Any know issues with the 6 speeds? During my research of these vehicles I noticed the reliability dropped significantly starting in 2017, I'm assuming a lot of this is with the engine tweaking and tranny change to 8 speed?

C21964 · March 3, 2020

I have a 2018 V6 SLT, and I am contemplating adding a supercharger, but because of the reported transmission issues, wanted to get some more miles under warranty first. I now have about 22,000 miles, with about 4,000 of those miles towing a 6000 lb trailer a lot of it in mountains, and some long climbs at a steady 4500 RPM. Other driving is a mix of short city drives and 80-85 mph on tollway.

I have never had any issues at all with the transmission, under any driving or towing condition. The trans temperature typically runs about 145 degF, but when towing runs about 190 to 215.

For a 2018+ 8L45E Has anyone had the transmission work fine to over 20,000 miles but then had issues after that? Thanks

clackp72 · May 3, 2020

Folks there is a class action lawsuit going on for this very problem with this Transmission .

https://gmauthority.com/blog/2019/04/gm-hit-with-class-action-lawsuit-over-alleged-8-speed-transmission-defect/

sille · June 26, 2020

2017 with 8 speed. Started experiencing shudder around 40,000 miles. Drive train warranty handled. Fluid flush and change has corrected my Colorado's transmission issue. Still concerns me though. Now 90% of time key won't relese after turning truck off.