if you're talking about the travel surging,
3 solenoids in a row on trans under air filter box,
take the outer ones(not middle) off and see if they are
shiny(not corroded), sometimes you can buff up the cores a bit,
or change core and solenoid,
that's for surging/ choppy travel at low speeds.
this is common you have to replace the valve block on the pump they develop hair line cracks internally if the truck has had a hard life this is the cause,unfortunatley they are very expensive,hope this helps