I'll bet its the linkage. The part that connects to the motor is usually plastic and has been known to break. The bad news is, at some point isuzu changed the design and after that you have to buy the whole linkage, not just the end peice that connects to the motor. I dont know what year they changed that.This info is from what I've read on the forums anyways.

--Dave

1999 Rodeo LS 3.2 4x4 5 Speed
32x11.50-15 BFG T/A KO on US Wheel 94 series
3" Lift - Rancho 9000x
Rear No-Slip Locker
Flowmaster 50 series SUV 2.25"

There is a very fine line between "hobby" and "mental illness." - Dave Barry