Shudder/Vibration Issue

TXGREEK · February 19, 2019

47K

2015 Silverado LT Midnight Edition
4.5” CST suspension lift
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chrispassas21 · February 19, 2019

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I’m going to take it in again soon I’m due for an oil change. Hope they try to help

2015 Silverado LT Midnight Edition
4.5” CST suspension lift
Sent from my iPhone using Tapatalk

TXGREEK · February 19, 2019

I’m going to take it in again soon I’m due for an oil change. Hope they try to help

2015 Silverado LT Midnight Edition
4.5” CST suspension lift
Sent from my iPhone using Tapatalk

Do your homework prior to getting to the dealership, know your warranty inside and out. Also, you’re not stuck using only that one dealership, you can take it to any GMC or CHEVY dealership. They do not communicate with one another unless same company

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ForumUser · February 19, 2019

chrispassas - tell them you will take it back to them every single time it shudders - and, then do it ... force them to go for a drive WITH you and record the RPM gauge ... they are slowing rolling you. The fluid change in mine appears to have completely fixed the problem.

TXgreek - could possibly be oil on MAF - they are incredibly sensitive ... not trying to start another war, but my understanding is that air filter mods result in performance improvement in a VERY small range - like at the max HP. Never made sense to spend the bucks to do it to me.

chrispassas21 · February 19, 2019

chrispassas - tell them you will take it back to them every single time it shudders - and, then do it ... force them to go for a drive WITH you and record the RPM gauge ... they are slowing rolling you. The fluid change in mine appears to have completely fixed the problem.

TXgreek - could possibly be oil on MAF - they are incredibly sensitive ... not trying to start another war, but my understanding is that air filter mods result in performance improvement in a VERY small range - like at the max HP. Never made sense to spend the bucks to do it to me.

I have been a little too nice, do you have the 6 speed?

2015 Silverado LT Midnight Edition
4.5” CST suspension lift
Sent from my iPhone using Tapatalk

ForumUser · February 19, 2019

Gah - sorry - Chris and TX! Mixed up names and topics ...

Chris, comment re shudder was meant for Eric with the 2018 6.2 and 8 speed.

TX - comment re MAF was meant for Chris ... been thinking more about the MAF and oil contamination ... could be the problem, but not clear. 6 speeds were not known for the shudder issue prevalent in the 8 speeds, were they?

TXGREEK · February 19, 2019

chrispassas - tell them you will take it back to them every single time it shudders - and, then do it ... force them to go for a drive WITH you and record the RPM gauge ... they are slowing rolling you. The fluid change in mine appears to have completely fixed the problem.

TXgreek - could possibly be oil on MAF - they are incredibly sensitive ... not trying to start another war, but my understanding is that air filter mods result in performance improvement in a VERY small range - like at the max HP. Never made sense to spend the bucks to do it to me.

IMHO, it’s more of a mental high than anything else. I’ve run cold can induction in prior vehicles and in all cases actually getting negative returns. It’s a mental high, that’s all. These engineers would’ve made a larger intake to make draw in more air to make more HP if they thought it would’ve helped improve against the competition. I’d rather change the stock air filter more often than install one of those. Last vehicle I had it on was my 14 with a 5.3, negative performance. This type of added kit only works positive performance if your motor is completely tuned (not canned tune) in addition to headers, exhaust, motor enhancements and much much, more. Back, starting in my teens, my stock Buick T Type and later in my 20’s a slant nose 930 destroyed every street legal hot rod that went up against me. Our trucks are designed for towing, hauling and going through drive thru’s lol. Just my opinion.

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TXGREEK · February 19, 2019

Gah - sorry - Chris and TX! Mixed up names and topics ...

Chris, comment re shudder was meant for Eric with the 2018 6.2 and 8 speed.

TX - comment re MAF was meant for Chris ... been thinking more about the MAF and oil contamination ... could be the problem, but not clear. 6 speeds were not known for the shudder issue prevalent in the 8 speeds, were they?

Both, issues are with both 6 speed and 8 speed

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ForumUser · February 19, 2019

TX,

Copy - however, from my limited reading the issues sound a bit different ... 6 speeds appear to clunk badly and not shift smoothly, whereas the 8 speeds are much more likely to shudder and rattle AND clunk badly on down and upshifts at certain points ...

Perhaps the new fluid will help the 6 speeds as well?

I am still amazed this sort of thing can even happen - given the development costs and opportunities to beat the shxx out of them during testing ...

"Life is a beta test ..."

ForumUser · March 30, 2019

Fluid change in my 2017 6.2 with 8 speed still doing well ... about 3k on it since change with zero issues.

Lamekurt · April 12, 2019

On 2019-02-19 at 1:29 PM, chrispassas21 said:

I have been a little too nice, do you have the 6 speed?

2015 Silverado LT Midnight Edition
4.5” CST suspension lift
Sent from my iPhone using Tapatalk

Did you end up getting the fluid change for your 6speed? I have an 18 6 speed and it shudders and clunks like crazy.

chrispassas21 · April 12, 2019

Did you end up getting the fluid change for your 6speed? I have an 18 6 speed and it shudders and clunks like crazy.

No. But I did just get a black bear performance tune and the transmission is basically how it should be from factory now.

2015 Silverado LT Midnight Edition
4.5” CST suspension lift
Sent from my iPhone using Tapatalk

MPJohnny5 · April 12, 2019

2 hours ago, chrispassas21 said:

No. But I did just get a black bear performance tune and the transmission is basically how it should be from factory now.

2015 Silverado LT Midnight Edition
4.5” CST suspension lift
Sent from my iPhone using Tapatalk

Could you expand , whatvwas it doing before and what have you noticed since the tune

chrispassas21 · April 12, 2019

Could you expand , whatvwas it doing before and what have you noticed since the tune

Before it would always clunk after letting off gas then coasting. It wouldn’t know what to do if I wanted to go fast. Justin turned off AFM under 45mph and cleaned up the shift points. It really does drive like a different truck. Still think I need to regear because of my tires but other than that I’m very satisfied

2015 Silverado LT Midnight Edition
4.5” CST suspension lift
Sent from my iPhone using Tapatalk

drumsbh · April 13, 2019

It's been 3 weeks now since I had the trans flushed a d new fluid added in my 2016 Sierra 5.3 with the 8 speed trans. The shudder is still gone! Love it!

I was out of warranty and had to pay out if pocket, the dealership which sold me the truck refused to do the flush for free. ( That's a long story, they pretty much hid the shudder from me). They wanted $700 to do the flush, I laughed. Went to the other local GM dealership in town and they charged me $350. I'll never go back to the other and am letting everyone else know as well how crooked they are.

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