GM 8-Speed Transmission Lawsuit Heats Up - Does Yours Shudder?

[FLfirefighter]

I have a 2017 GMC Canyon which I bought new. I have had the hesitation issue while accelerating after only a few months and a surge/jerk when coming to a stop as well. I’v taken it to the dealership for repairs 5 times!!!

1st repair they performed a transmission flush, which did not work.

2nd repair they replaced the torque converter, which did not work. 

3rd repair they again tried trans flush, failed  again.

4th time was a final repair attempt under the lemon law where they REPLACED THE WHOLE TRANSMISSION... and guess what, problems still continued! 

Went to a BBB Hearing against GMC to get them to buy their faulty product back but was rejected. GMC claims the issues haven’t caused serious harm to anyone yet, still works as they see permittable, and convinced the hearing arbitrator that a new vehicle with all these issues and repairs on it’s record does not affect the resale value. This is ludicrous!

A 2017 truck with five repairs including a replaced tcc and transmission will dramatically decrease its value especially since the issue continue. And GMC wants someone to be injured before they address a well known issue with their products. I’m a Firefighter-Paramedic who’s responded to many motor vehicle accidents and for GMC  to ignore a preventable hazard like this is unacceptable. 

 

[mnm99]

Just brought my 17 in for my brake booster pump failing. I asked them to check the tranny again, for the 5th time now. Every service or recall I bring it in and complain. They always come back with " Its normal, No problem, Couldn't find a problem" this time I drove with a tranny tech and he heard the 3-1 clunk. They said they want to drop the pan. If there are no shavings, they want to change the valve body. If there is they will go further. Of course there were no shavings and changed the valve body. This is the kicker.... When she told me it was ready she flat out said they are not doing another thing on this tranny unless it's a major problem. So if it still clunks , I guess it's normal...! She said if the tech drives it like 25 miles, it happens 2 times, it's not a problem. I said ok so how many times would it happen in 25000 miles? Because that's how much I have on the truck. That's a lot. I'm done with GMC.... And to make it better, the person before me on line with the same counter person complained about the SAME thing I did.

[Daryl Z71]

Had my 2015 at the dealer two weeks ago now for them to change out the fluid. It made the transmission shift a lot better for sure, but I still have some clunking and confusion from the transmission sometimes. If I drive the truck in manual mode it is a lot better because I can limit how much it shifts. The speed limit in town here is 25 so I run around town in M4 until I get to the 35 zone and then let it go up to 5th gear. This honestly helps a ton. It sucks for sure, but GM isn't the only one with the clunking. My Boss for the IT company I work for part time has a 2018 F-250 with the 6.2L & 6 speed trans and it has the clunking issue just like my Silverado.

[Jim Meshefski]

Jim Meshefski,

I have a 2016 GMC Sierra with an 8 speed that has shifted poorly from first to second up shifting, and poorly down shifting at slow speeds.  My vehicle has 230000 miles and I have had the fluid and filter changed at 50k which corrected for about another 30k miles,  I had the converter changed at 130k with the old style fluid, however, a new part number torque converter; problem went away for about 30K miles.  The fluid was changed once again at 170K with the new style of fluid and the problem went away for about 20K mile.  I had the fluid changed again at about 210K miles with the new fluid and it works for about 10K miles.  I now have 230, 900 miles on the vehicle and its is worse now then its ever been, shuttering at about 1350 rpm and its to a point where it bangs when shifting from first to second gear when its cold.  It seems to operate the best when the transmission temperature reaches 160 degrees, however, it never really goes away.

 

I have a 2013 Sierra with a 6speed transmission with 333,000 miles and it shifts perfectly.  As you can see, warranty is out of the question, however, I will either get a  new design torque converter if I can find one, or a new vehicle that won't be GM.  

[DonkukoRST]

Have 2019 RST silverado and having lots off issues with the transmission only has 1500 miles and it's been in the dealer twice in less than a month any suggestions 

[Chad2815]

Mine shudders and hard downshifts. Been flushed 3 times, right now its better but still there. Hopefully the new Tundra is nice because this is probably my last GM. Not because of this issue because I know stuff breaks, but because of the way they have handled my repairs. Its like pulling teeth to get them to do anything. 

[benelli]

On 4/25/2019 at 5:34 PM, HondaHawkGT said:

So you haven't been in for the new TSB?

https://gm-techlink.com/?p=11127

 

TCC Shudder and New Mobil 1 Fluid Exchange

January 31, 2019

 

"A new transmission fluid exchange procedure and a new formula of Mobil 1 Synthetic LV ATF HP transmission fluid have been released to address torque converter clutch (TCC) shudder conditions on 8L45 and 8L90 8-speed automatic transmissions (RPOs M5N, M5T, M5U, M5X) in some 2015-2017 Escalade, Yukon; 2015-2018 Silverado, Sierra; 2015-2019 Corvette; 2016-2018 CT6; 2016-2019 ATS, CTS, Camaro; and 2017-2019 Colorado and Canyon models."

 

"The TCC shudder condition is related to moisture content in the transmission fluid. The current fluid tends to be hydroscopic, or absorbs moisture, which increases the chance of TCC shudder. There are three different fluid exchange procedures to follow, depending on vehicle application, so that an acceptable concentration of the new HP fluid is achieved in the transmission."

 

"The new Mobil 1 Synthetic LV ATF HP transmission fluid is now available to U.S. dealerships through your local GM Oil Distributor. The new Mobil 1 Synthetic LV ATF HP transmission fluid is available in quart bottles (GM Part Number 19417577) and, for a limited time, in 55-gallon drums (GM Part Number 19417904) (Fig. 12) in most locations. Drum production ended in January 2019. The GM part numbers are not on the product. The Mobil 1 Synthetic LV ATF HP fluid and the required tool kit will be available to all Canadian dealerships by the end of March 2019. GM Part Numbers for 0.946 liter bottles will be provided at that time."

Had that done . It’s worse . In reality there no fluid in the world going to fix a bad designed transmission.

[benelli]

On 10/28/2019 at 6:59 PM, mnm99 said:

Just brought my 17 in for my brake booster pump failing. I asked them to check the tranny again, for the 5th time now. Every service or recall I bring it in and complain. They always come back with " Its normal, No problem, Couldn't find a problem" this time I drove with a tranny tech and he heard the 3-1 clunk. They said they want to drop the pan. If there are no shavings, they want to change the valve body. If there is they will go further. Of course there were no shavings and changed the valve body. This is the kicker.... When she told me it was ready she flat out said they are not doing another thing on this tranny unless it's a major problem. So if it still clunks , I guess it's normal...! She said if the tech drives it like 25 miles, it happens 2 times, it's not a problem. I said ok so how many times would it happen in 25000 miles? Because that's how much I have on the truck. That's a lot. I'm done with GMC.... And to make it better, the person before me on line with the same counter person complained about the SAME thing I did.

I hear you brother . Mine has been in more times for this crap . They won’t do anything. Never going to buy one of these junks again . Just waiting for some other dealer incentives with other manufactures then this junk is traded in . Gm should be boycotted. And no one should by any of there vehicles. Then you would see how they would move there a***s to fix sh*t.

Edited December 13, 2019 by benelli

[Jaychevy81]

My 18 has had the trans issue since day 1. Clunking hard shifting. Banging on up and down shifts. Has been to the dealer 3 times 3 relearns and a flush. I installed a set of traction bars on Sunday. Since then not 1 clunk not 1 bang nothing it shifts fine. No banging I’m not saying it’s a fix but I believe the axle wrap combined with a shitty trans made it worse. At least now I can live with it.


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[Thomcat]

On 5/20/2019 at 2:29 PM, econometrics said:

Maybe. But I can say that my 2019 8 speed has improved significantly as I've owned the truck over the first 2000 miles. 

Really loved two other '19 colors but resigned to Red Hot because color was less important than picking out the pick of the litter with a "1" VIN, GM mfrd. no rattle front axle and newer MQE tranny OEM with Mobil 1 HP juice. No refill for me, no telling what damage may have been done prior to the flush and fill with the "good stuff".

 

Only minor complaint was a hard first 1-2 upshift after an overnight cold which I attributed to an accumulator bleed down after a long sit. Just hit 4000 and the computer must have received it's learning diploma for my moods and driving speeds and adjusted servo refill rates because now it shifts 1-2 and all other gears smoothly first time every time regardless of a slow crawl or a break neck 0-60+.

[econometrics]

5 hours ago, Thomcat said:

Really loved two other '19 colors but resigned to Red Hot because color was less important than picking out the pick of the litter with a "1" VIN, GM mfrd. no rattle front axle and newer MQE tranny OEM with Mobil 1 HP juice. No refill for me, no telling what damage may have been done prior to the flush and fill with the "good stuff".

 

Only minor complaint was a hard first 1-2 upshift after an overnight cold which I attributed to an accumulator bleed down after a long sit. Just hit 4000 and the computer must have received it's learning diploma for my moods and driving speeds and adjusted servo refill rates because now it shifts 1-2 and all other gears smoothly first time every time regardless of a slow crawl or a break neck 0-60+.

Mine is shifting incredibly smooth now at 7500 miles, too. 

[Rita Davidson]

My 2017 GMC Canyon had gone to service a total 21 day with a replaced rebuilt transmission that  Is still defective. The dealer is claiming nothing is wrong, but it’s making noise when put into gear and downshifting is hard. All we want is what we paid for a dependable truck , one we don’t have to fear to drive.

 

[Thomcat]

On 12/18/2019 at 1:05 PM, econometrics said:

Mine is shifting incredibly smooth now at 7500 miles, too. 

Temperature in the teens today. looked closely at the first 1-2 hard shift  and it did it once, first time........no engine flare or rpm rise at shift point just a drop in the tach meaning it's just a hard shift but no slippage......Mobil1 engine oil running at 70 p.s.i and tranny temp at 20 F. at this shiftpoint. Less than 3 mins.  later tried it again engine oil dropped to 40 psi and tranny temp 40 and a much softer 1-2 shift again with no slippage. Less than 5 mins. from starting the 1-2 shift was once again smooth, almost unnoticible, as were all further upshifts. Parked for 4 hours and started again with tranny starting temp at 70F+ and engine oil at 40 p.s.i and every shift was smooth as silk including the first 1-2 upshift.

 

My guess is at least with my MQE tranny with Mobil HP the cold temperature and high oil pressures cause a hard shift and won't be 100% solved other than by moving to FL (or TX). Tranny fluid must have something in common with Ketchup, stiff when cold, but once you heat it or shake it and get it moving it flows just fine.

 

Besides, temperature sensitive trannys are nothing new,  first few shifts on my cold Chrysler Torqueflites were both delayed and hard. As long as I know what it is.....seems normal and easy to live with......it's only a machine governed by basic physics and nothing a dealer can cure and taking it in would only be asking for problems.

[charles willette]

2018 camaro'2 s s ,shudder \hesitation had trans flush ,didn't work had tourgue converter replaced,brought back in couldn't simulate hesitation so I guess  didn't happen( how come dealer can't properly test transmission) had the oil changed car sitting driveway leaked out there towing car back to dealer they can't manages oil change so no faith they can fix transmission

[charles willette]

Traded my 2015 camaro because of nagging ignition issues only for them to issue recall after warranty up,bought a 2018 that they knew had transmission problems in April of 2019,feel swindled