My rears went out after a few years back and showed signs of it. Rear of the truck just wasn't riding well and there was some signs of fluid leakage. I figure if it had happened in the front the ride might not have been as bad what with the IFS VS the solid axel rear. I pulled mine off and just attempted to run them through their cycle and found that way too easy to do. Hadn't been hittin' the gym they had just bought the farm. You could try and do that and see if they smoothly expand and compress. Should be pretty hard to do by hand and should work smoothly.