I currentley have have a 99' with a 01' 5.3 engine and matching automatic transmission that was recently installed. the issue at hand, drove fine at normal speed then while in in drive it slipped out of gear, fell back in gear, then a mile down the road it would not go into any gear as if it was in neutral. I have checked the fluid even though it did leak some transmission fluid out "after" I had it towed and it is a bit over the mark on the dip stick. I checked the shift cable and it is moving the gear lever on the transmission.

One note, the 4wd selector switch on the dash is blinking if I try to put into auto 4wd or 4wd hi or lo ( it does not blink when in 2wd mode). I also know that my actuator to the transfer case is shot. I guess what I'm curious about is if the selector switch could have thrown the transmission into a flat neutral ? I jsut cannot under stand why it would drive fine then just have no gearing. Thanks in advance.