vibration on modified truck

[TT32VGT]

i have a '17 slt 4x4 z71 that has a 6" fabtech perf kit and 35" wheels tires..

 

recently took it into a shop.. taking to another shop next time, long story..

 

i noticed a vibration.. between 1-2k rpms, 40-77mph.. you can feel the vibration in the steering wheel and the whole truck really.. if throttle is held or its on cruise control you can see the rpms jump a few hundred rpm when the vibration comes through..

 

has me thinking a wheel balancer came off... or maybe its bc i removed the air dam? maybe the engine is getting more air flow now and the tune isnt accounting for that?

 

 

thoughts?

[2017SierraSLT]

Does it do this in V4 mode?

[TT32VGT]

no v4 was disabled with the tune

[x219c]

If the RPMs are jumping, could it be the torque converter?

 

 

Sent from my iPhone using Tapatalk

[2017SierraSLT]

Could be related to the torque converter lockup.

[TT32VGT]

hmm thats worrisome.. im guessing bc of the lift and tires/wheels that warranty wont cover?

[TT32VGT]

I’m abt to take it to the dealership. Def seems converter or trans related

do y’all think it will be covered?

anyone heard of converter or trans issues on the 8spd?

thx

[2017SierraSLT]

If they can prove the lift hastened or caused the issue, GM will deny coverage. The torque converter shudder is common in the 8 speed. To correct, GM flushes the trans a couple of times, and refills with a fully synthetic fluid.

[Irby1757]

On 10/3/2017 at 1:12 PM, TT32VGT said:

no v4 was disabled with the tune

 

Remove your tune before taking it to the dealer. 

[jagabom (Esquire)]

Keep us posted.

Jim