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My 8-speed Auto Transmission is a Stumbling Drunk

InVision

By InVision
in Engines & Drivetrain

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  • 2 weeks later...
InVision Enthusiast

InVision

Posted
  • Author
Posted
On 1/22/2019 at 2:35 PM, InVision said:

Just pickup up Truck.

 

They flushed the transmission, convertor and lines, changed the fluid multiple times, replaced & reset the shift adapter.  Verified concern: FOUNDTCC Shudder.  Not sure what that means all considered.

 

THE TRUCK RAN GREAT & SMOOTH WITH NO STUMBLING OR ERRATIC SHIFTING.

 

If this is a sign of the future, I am in LOVE with my truck once more!!

 

M

BAD NEWS !! My GMC Denali has learned to be a stumbling drunk again.  Must be my driving as I am told that the Shift Adapter learns.  Back to the Shop !!

 

M

mjm-1957 Enthusiast

mjm-1957

Posted
Posted

Its not your driving, cut your losses and get rid of that headache. It will be trouble to the day you get rid of it.

  • 1 month later...
Cujo Enthusiast

Cujo

Posted
Posted

Took my 2017 in for scheduled maintenance (oil, filter, etc) and asked them to perform the shudder test. Sure enough, my truck “qualified” for the new flush. However, now as it turns out, the torque converter is bad, too, at 64,000 miles. Of course the drive train warranty is up at 60,000. Good thing I bought the extended warranty which covers me right up to 115,000 miles. Been at the shop for 4 days now. They provided me with a loaner. A Chevy Equinox. I sure do miss my Sierra SLT!

Jacoby Enthusiast

Jacoby

Posted
Posted

I just got an email about a class action lawsuit on the 8 speed. Sounds like GM dropped the ball on that bad boy

dc1515 Enthusiast

dc1515

Posted
Posted

I have roughly 41k on my truck now and it has had erratic shifting from the moment I bought it with 20 miles on it. I am considering the new 10 speed Yukon. I have heard good things about it.

  • 2 weeks later...
Cujo Enthusiast

Cujo

Posted
Posted
On 4/4/2019 at 10:43 PM, Cujo said:

Took my 2017 in for scheduled maintenance (oil, filter, etc) and asked them to perform the shudder test. Sure enough, my truck “qualified” for the new flush. However, now as it turns out, the torque converter is bad, too, at 64,000 miles. Of course the drive train warranty is up at 60,000. Good thing I bought the extended warranty which covers me right up to 115,000 miles. Been at the shop for 4 days now. They provided me with a loaner. A Chevy Equinox. I sure do miss my Sierra SLT!

Update:  The torque converter was bad from all the metal shavings found during the flush.  They dropped the transmission and found metal shavings, too.  Unfortunately the transmission had to be replaced but again, fortunately for me, my extended warranty took care of the bill.  I've had it back for a few days now and so far it's smooth as silk.  No more hard shift changes from first to second and from second down to first.  And no more shuddering between 15-45 mph.  And, I've got a new transmission with a 3 year, 100,000 mile warranty.  My GM dealer was absolutely fantastic during the entire ordeal.

YukonXL04 Enthusiast

YukonXL04

Posted
Posted

I have a 18 6.2 with the 8 speed, overall I love how it runs, drives and shifts. Way better than the 17 5.3 6 speed my uncle has. The shifts are smoother and never seem to be in the wrong gear. I like it alot. But I have 1 weird issue when it's cold, the first shift from 1st to 2nd it has a weird delay sometimes. Enough that if I'm going up a hill, when it happens it lunges my body forward a little bit. Only happens every once in a while though. 

Hillwood Enthusiast

Hillwood

Posted
Posted
4 hours ago, YukonXL04 said:

I have a 18 6.2 with the 8 speed, overall I love how it runs, drives and shifts. Way better than the 17 5.3 6 speed my uncle has. The shifts are smoother and never seem to be in the wrong gear. I like it alot. But I have 1 weird issue when it's cold, the first shift from 1st to 2nd it has a weird delay sometimes. Enough that if I'm going up a hill, when it happens it lunges my body forward a little bit. Only happens every once in a while though. 

That's normal,  GM published a bulletin on it.. Clutch oil fill time they say.

YukonXL04 Enthusiast

YukonXL04

Posted
Posted
1 hour ago, Hillwood said:

That's normal,  GM published a bulletin on it.. Clutch oil fill time they say.

Yea I have gotten over it. Kind of annoying. But I absolutely love how mine drives otherwise.

InVision Enthusiast

InVision

Posted
  • Author
Posted
On 4/5/2019 at 11:50 AM, Jacoby said:

I just got an email about a class action lawsuit on the 8 speed. Sounds like GM dropped the ball on that bad boy

Does anyone care to share how tho become part of this class action lawsuit?  PM would be most appreciated.

 

M

InVision Enthusiast

InVision

Posted
  • Author
Posted

Well, Truck is bad again.  Back for the 4th time.  Got real bad news as the new Sierra Denali is 4 inches longer and won't fit in the garage :-(.  Really was looking forward to get a 6.2L 10speed...

 

Submitted claim to join class action suite (pretty sure that won't help).

 

A friend suggested leaving keys in the truck, can'y bring myself to do that.

 

Checking on Florida Lemon Law but it is almost impossible without lawyer.

 

M

InVision Enthusiast

InVision

Posted
  • Author
Posted

Pretty sure GM lawyers are involved now.  This was the 4th time I have took truck in for Stumbling Drunk transmission. Now they said that it is, and I quote, "Normal".  So if they have problems shuddering and such it is now normal.

 

1st time - Works as it should (1 day)

2nd time - Changed fluid per TSB and reset Adaptive Shift Module (3 days)

3rd time -  Fixed 2 issues with garage mode.  I have not a clue WTF that is. (3 days)

4th time - Normal (3 days) what a joke !!

 

Not even sure what to do...

 

It is a nightmare !!

 

M

  • 1 month later...
MD11G200 Enthusiast

MD11G200

Posted
Posted

Thought I would check in on this topic, has anyone had any luck with getting the clunky transmission problems fixed? What about the lawsuit from what i can tell only applies to certain states, I am hearing and getting mixed reviews that the latest new transmission fluid( released back in early 2019) is helping some folks.

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