Shake or Vibration Issues

[fishrman]

57 minutes ago, BigTex4x4 said:

Mine did the same thing a couple weeks ago on my 17 Sierra cc 5.3 z71 4x4. Dropped it off at the mechanic and my transmission was completely shot, not even rebuildable. The problem started at the torque converter. Did a lot of research and turns out there’s a class action lawsuit against gm on these transmissions. $4,300 out of my own pocket. I’m pissed to say the least 

Was that the 8 speed or 6?

 

[BigTex4x4]

It was the 6 speed

[fishrman]

17 minutes ago, BigTex4x4 said:

It was the 6 speed

Interesting since that is the same as mine and they say there is no service bulletins for the 6 speed and I think the law suit is just for the 8 speed. I am still talking with GM about mine and have an open case on it. So far, I have had a hard time getting them to try to put Mobil 1 in as that seems to help those who have the 8 speed.

 

[BigTex4x4]

I had read the threads to flush the trans fluid and use Mobil 1 and if that didn’t work to replace the torque converter, I told my mechanic (I didn’t realize that the class action suit was for the 8 speeds) that GM had made those recommendations. He said when he took the pan off of the transmission it was completely full of metal shavings and beyond repair. Truck has 75,000 so no longer has a warranty. 

[Snoringbear]

15 hours ago, BigTex4x4 said:

Mine did the same thing a couple weeks ago on my 17 Sierra cc 5.3 z71 4x4. Dropped it off at the mechanic and my transmission was completely shot, not even rebuildable. The problem started at the torque converter. Did a lot of research and turns out there’s a class action lawsuit against gm on these transmissions. $4,300 out of my own pocket. I’m pissed to say the least 

Where did you get your information that there’s a class action lawsuit on the transmission?  If you could share your source it would be greatly appreciated by me and probably many others.  Thanks.

[BigTex4x4]

If you google class action lawsuit filed against GM for bad transmissions it pops up multiple articles. The suit was filed September 30 2019 by Cohen Milstein for the 8L90 and 8L45 transmissions. My transmission is a 6 speed but still did the exact same thing that the lawsuit claims the 8 speeds do. There were multiple people trying to get GM to do a recall but they didn’t 

[fishrman]

21 hours ago, BigTex4x4 said:

I had read the threads to flush the trans fluid and use Mobil 1 and if that didn’t work to replace the torque converter, I told my mechanic (I didn’t realize that the class action suit was for the 8 speeds) that GM had made those recommendations. He said when he took the pan off of the transmission it was completely full of metal shavings and beyond repair. Truck has 75,000 so no longer has a warranty. 

Sad!! Lady with GM told me to take it to the shop again but to call her before I take it in. Hoping they plan on changing the fluid out for me even though it is the 6 speed and not the 8 as I think it has the same issue as the 8.

[Snoringbear]

17 hours ago, fishrman said:

Sad!! Lady with GM told me to take it to the shop again but to call her before I take it in. Hoping they plan on changing the fluid out for me even though it is the 6 speed and not the 8 as I think it has the same issue as the 8.

I had the TSB performed on my 2015 eight speed tranny with the prescribed Mobile 1Blue Stripe tranny fluid, three flushes, drive, reprogram, etc.  worked ok for awhile but gradually started making those low speed/gears hard shifts again.  But, problem wasn’t as bad as originally I must say.  However, I now do a little trick that I got off this thread awhile back, which is;  Every few days When I make my first drive of the day I start off in Manual mode and run the tranny through the gears up and down, usually 1st, 2nd, 3rd.  I have to go through three or four stop signs to get to the highway.  Anyway, tranny will make low speed shifts smoothly for a few days.  Personally, I think the low speed hard shift problem could probably be handled by reprogramming the tranny to start off in 2nd gear unless in Tow Mode.  Some high end sports cars have programmed their trannys to take off in 2nd gear unless in Sport Mode.  
Btw, did some research on a comment upstream that there’s a class action suit underway.  From what I’ve read it’s a dead issue. Ain’t nothing gonna happen. ...

 

[flyingfool]

did you do a bench test on the TECH-M? make sure there are no leaks and all check valves are holding,  I would leave it in Manual 4-5th also play with tow haul to increase line pressure to clutches

definatly needs proper trans professional to diagnose

 

there are two model torque converters, one is a dud, and the other one is semi reliable. you can also try a converter from the 6 speed ZL1 camaro, its built better and has  around 2300-2500 stall

Edited September 27, 2020 by flyingfool

[BDB001]

Hi, It's my first time on any forum and I'm sure it's been said before but my truck is a lemon!! I own a 2018 gmc sierra 1500 elevation edition with a 4.3l and six speed trans. I've had every vibration has most of you, from the vibration when it falls on 4cyl in every situation, worst when running at approx 50 to 70kmh. I have the vibration when running more than 60 kmh and worst as a get to 100 kmh, sometimes it gets so bad I have drop under 100kmh. I also have a bad vibration under my feet and gas pedal when I'm at 2000rpm, so there's always a vibration present. I brought it at the dealer at least 3-4 times but the service manager says every time that the problem wasn't present when the tech tried it out. Once I tried it out with the tech and he told me they knew there was a problem but gm tells them not tempt any repairs, then that same service manager tells me it's normal. I even told the sales manager that I'd like to trade it in even if I loose money, even the dealer doesn't want it cause she told me she'd take pictures and try a wholesaler. so I got screwed when I bought it and I'll get screwed when I change it. It feels good just saying it, thanks for that... 

[Bikemobile]

15 hours ago, BDB001 said:

Hi, It's my first time on any forum and I'm sure it's been said before but my truck is a lemon!! I own a 2018 gmc sierra 1500 elevation edition with a 4.3l and six speed trans. I've had every vibration has most of you, from the vibration when it falls on 4cyl in every situation, worst when running at approx 50 to 70kmh. I have the vibration when running more than 60 kmh and worst as a get to 100 kmh, sometimes it gets so bad I have drop under 100kmh. I also have a bad vibration under my feet and gas pedal when I'm at 2000rpm, so there's always a vibration present. I brought it at the dealer at least 3-4 times but the service manager says every time that the problem wasn't present when the tech tried it out. Once I tried it out with the tech and he told me they knew there was a problem but gm tells them not tempt any repairs, then that same service manager tells me it's normal. I even told the sales manager that I'd like to trade it in even if I loose money, even the dealer doesn't want it cause she told me she'd take pictures and try a wholesaler. so I got screwed when I bought it and I'll get screwed when I change it. It feels good just saying it, thanks for that... 

A comprehensive tire balance ( actually make them move the tires on the rims to get the lowest weight possible) and a tune deleting the AFM has made my truck 1000 times better. Its worth a try if you have to keep it. 

[TheLemonLawMan]

If you live in California and drive a 2014-2021 GM vehicle that has received at least 2 warranty repairs we can help get you compensated. 

[FredB]

My 2018 Chevy Colorado has the Chevy Shack. I called GM and was told there are no recalls but if I took it to a GM dealer the transmission was still under warranty.

[Mattfi1]

I have a 2018 Chevy 2500 Express Van with a Explorer conversion and I am having a severe right front end vibration after I hit a bump or pothole.  It has happen at 65 mph and again at 45 mph.  The dealer has said it was the transmission and he changed the fluid and filter.  Well 200 miles later I had it again.  Not sure what to do but I'm contacting the dealer again and see what they say this time.  [email protected]

[Drew71]

On 8/5/2013 at 11:48 PM, Stex said:

 

I have had wheel balance trouble that came and went on different roads. If it rides smooth on smooth roads and seems out of it on not so smooth roads it could be balance. Rough on smooth roads with passenger seat shaking is rear balance or drive shaft,

 

Did the dealer check to see if tires out of round? Even discount tire has replace a Michelin for me that my independent on the truck balance shop said was to far out to even true. Discount agreed. Just hunting here. Hope solved soon.

I had the same issue. Balanced rear shaft helped a ton. Can't tell if it took it all as I have worked rotors to replace too. But definitely made a drastic improvement.