Intermittant shudder at low rpm while driving...

[Robert Garry]

For a month or so now I get an intermittent shudder or vibration at low rpm. It disappears at higher rpm or when I come off the throttle...any thoughts

 

[rav3]

Have you had the GM TSB fluid change & upgrade done on this 8 speed? How many miles on it?

https://gmauthority.com/blog/2019/08/tsb-seems-to-fix-8-speed-automatic-gm-transmission-problems/

[pokismoki]

1.try running in 7th gear to disable the DoD ,

2.then try driving in tow haul  

3.try mixing tow haul and 6th or 7th gear together

4.can also try tapping the break pedal durring shudder to disconnect TCC, but this may not work on newer GM transmissions. it usually worked on the older systems

 

let us know what you find out

Edited June 15, 2022 by pokismoki

[2003Z71]

Had the same issue, have the dealer change the transmission fluid to the new version.  I also have an Range module to stay in V8 mode all the time.  Problem solved 

[Robert Garry]

Thanks for the reply...having the transmission fluid changed tomorrow at the dealer...can they program it to stay in V-8 all the time? Incidentally, I was running on 87 octane when not towing. I filled up with 91 octane recently and seemed to reduce the problem...could it have been missing at low RPM in V-4 causing it to run rough. Thoughts

[JimCost2014]

6 minutes ago, Robert Garry said:

Thanks for the reply...having the transmission fluid changed tomorrow at the dealer...can they program it to stay in V-8 all the time? Incidentally, I was running on 87 octane when not towing. I filled up with 91 octane recently and seemed to reduce the problem...could it have been missing at low RPM in V-4 causing it to run rough. Thoughts

No on the tune, not a dealer option.

 

Stick with premium, your 6.2 will be much happier living up to it's potential.

 

Make sure that the Mobil 1 Blue Label is used, it will make a huge difference, speaking from experience. 

 

Good looking truck, and welcome to the site my neighbor to the North!!!

[Robert Garry]

Thanks for the advise, neighbor to the south! Love Washington State! 

[Z45]

GM Dexron HP

"The base stock of old fluid (19355656) has the ability to attract low levels of moisture, which can cause degradation of the coefficient of friction of the fluid. The new fluid (19417577) has a new GTL (Gas to Liquid) base stock that is able to tolerate more moisture. Shuddering transmissions and torque converters have been recovered with the new fluid. New transmission fluid tests have been developed due this issue to prevent it from occurring with new transmission fluids."