On a prior thread I mentioned that I was going to experiment in order to diagnose the issue.

I noticed that the bounce began after the first tire rotation. After rotating the tires for the 3rd time - no improvement -

Scheduled an appointment with the dealer prior to having 12K miles on the clock.

They did the new 11-4-XX flash, changed the front shocks, steering dampener and did the front end alignment (as well as a few other minor issues).

The alignment included adjusting the camber and castor.

The end result is that the transmission shifting issue is going great, so far. The suspension is behaving much better, to the extent that the "bump" I travel over each day does not shake the truck or steering wheel.

 

Glad to hear they took care of you, Randy!


The remaining issue sounds a lot like tire balance to me. They did balance all 4 wheels....right?

 

Good to hear Adobe. I had my front end aligned three times before the front wheel shimmy went away. It got better each time they adjusted it, but I wasn't satisfied completely until it was all gone and the steering wheel was once again square with the world. After the second alignment, the truck pulled to the left and the steering wheel steered left. So back we went to the alignment shop. End result is it feels better when I hit cracks in the road or bridge abutments and no longer pulls itself into traffic.

I hope the tranny shifting issue is finally resolved. I have similar harsh shifts and gear searching going on. Not as severe as it once was though. I had the dealer do a pcm flash and reflash the 400/800 upgrade back in March when they done my first oil change at 5k. It seemed better after that service visit. But, there is still the occasional hiccup in the gear selection. I haven't experienced the flaring issue a lot of you guys have spoke of. Maybe once if I use my imagination. Hope we can put this tranny thing behind us once and for all.

BTW, my truck is a job 1, June 10 build date.

 

No, they didn't balance all 4 tires. Guess that we will need to see how it goes.