shifting up and down at 35 mph

[mitchC]

2006 3500 4x4 SRW 234000 miles transmission is shifting at 35 mph up and down going uphill.
I’m thinking something needs a replacement. Any ideas appreciated.Thanks

 

[cerberusiam]

Probably just new electronics and a shift kit would solve that. BTW, that is the typical shuttle shift that happens with a stock setup on these trucks.

 

[Prairie Dog]

Been trying to get my buddy with a nice 06 to fix this for a long time. It's got to be bad for it.
What are the results of shuttle shift going on too long?

Scott