These tips won't fix the problem, but will mitigate the effects:
1) Avoid shifting directly from Park to Reverse, always shift directly from Park to Drive first, then back to Reverse.
2) When shifting from Park, try to do so quickly and accurately, and pull back on the lever at the same time.
3) Avoid parking on steep hills, unless you engage the emergency brake before selecting Park.
4) Avoid sudden acceleration followed by sudden deceleration, unless you want the tranny to slam down into lower gear and throw a code.
5) If Reverse won't hold on a hill, feather the brake at the same time as you give it a little gas.
6) When the above suggestion fails to work any longer, stop parking on hills.
7) If 2nd gear starts to fail, over-rev past the normal shift point, and let the trans/engine drop down into gear, then accelerate normally.
8) Try to shift from Park into Drive right after you start the engine as the revs are slowly starting to drop.
9) Do not let your wife or kids drive your truck once the tranny gets this bad.
10) These tips can usually be avoided if you are rich and/or have less than 100k miles
YMMV
=[8^)
