2017 silverado 5.3 6L80E

Stownse · December 8, 2021

So after looking through numerous posts trying to narrow down what could be going on with my truck i figured i would just ask perhaps someone else has seen this.

So i bought the truck 6 months ago with 53xxx miles its a 2017 LT silverado with the 5.3 6 speed crew cab short bed. I dont drive it much because i have a work vehicle that i daily drive. OD is just over 56xxx miles now and i took it out for a drive this past week and noticed under harder accelleration ( over 2000 rpm ) a hard vibration that increases in severity with acceleration only especially going uphill. The second i let off it dies off.

Checked and did the following since, checked the U joints no play that i can see. Transmissoon fluid/filter change. Engine braking doesnt seem to replicate the vibration (i.e. going down a hill shifting down causing rpm to go above 2000).dont know if this rules out engine mounts and or torqe converter or not. Shifting is a little smoother since the fluid change. Slight clunk shifting R to D. I feel the vibration especially in the wheel and gas pedal.

If anyone could help it would be appreciated.

Edited December 8, 2021 by Stownse

M1ck3y · December 9, 2021

I cant say if this applies to you. But my 8spd did that for a little while (steering wheel/pedal vibration) before it eventually turned into the chevy shake. Trans flush with new fluid mostly fixed it. But seeing as you've already done a flush, it could potentially be your torque converter on its way out.

Sounds like something that needs to be properly diagnosed.

Nice paint!

Edited December 9, 2021 by M1ck3y

Stownse · December 9, 2021

11 hours ago, M1ck3y said:

I cant say if this applies to you. But my 8spd did that for a little while (steering wheel/pedal vibration) before it eventually turned into the chevy shake. Trans flush with new fluid mostly fixed it. But seeing as you've already done a flush, it could potentially be your torque converter on its way out.

Sounds like something that needs to be properly diagnosed.

Nice paint!

With your 8speed did you notice the vibration when shifting down/engine braking? I am going to double check the engine/tranny mounts as well. Hoping that it is something i can fix i really love this truck.

And thanks the 2 tone fade is what really caught my eye on the truck.

rlcole321 · December 9, 2021

It might be an alinement or suspension issue, hard excel. lifts some of the weight off the front tires and it may be a wheel shimmy, just a thought. (also make sure it is in 2 WD)

M1ck3y · December 9, 2021

2 hours ago, Stownse said:

With your 8speed did you notice the vibration when shifting down/engine braking? I am going to double check the engine/tranny mounts as well. Hoping that it is something i can fix i really love this truck.

And thanks the 2 tone fade is what really caught my eye on the truck.

No, in my case it was during cruising at a constant speed. Then it went to rpm fluctuations (+/-200). Then onto full vibrating like crazy, basically everywhere.

Still ticked about that. I had the truck looked at multiple times through out that transition. Wasn't until you could use it as paint shaker did they actually do something about it.

superdave160 · December 11, 2021

When you changed the transmission fluid, did you put in the "new" transmission fluid? I don't recall what it is called, but if you're experiencing vibrations from your transmission, then the dealer will flush your transmission and add the new fluid. As I understand it, it is supposed to make the torque clutch last much longer. There is a TSB on it and they are supposed to do it for free. You could be feeling the torque converter clutch slipping.

CamGTP · December 11, 2021

The 6L80e does not require a different fluid, that is only for the 8L90e transmission.

Stownse · December 20, 2021

Just a little update i have been super busy as of late. Vibration problem has been solved. It has been a combination of diff fluid change (front and rear), alignment, trans flush, tire rotation and wheel road force balance. The last little bit of vibration i felt i realized the truck had been in AWD/auto mode vs rwd and the vibration was just the front tires breaking free

Runs like a dream now, shifts are super clean. Unfortunately now i need to do oil/filter next month.

Forgot to add the shop that did my alignment was like "the 6 inch lift is why you feel the vibration" before they did the alignment.

Edited December 20, 2021 by Stownse
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