I noticed some poping or nocking from the rear of my 2001 F-150 Supercrew, it sounds like it's coming from the rear axle. The sound in intermitant. Any ideas? Can it be driven?

 

does it have a limited slip and does it happen around corners. yes it can be driven. Change fluid hope for best use LS aprroved fluid or put in an additive. Clutch packs can be purchased reasonably. check for pinion slop and leaks.

 

I solved the problem, it was the parking brake drum shoes. Behind the rear disc brakes, there is a parking drum brake. The pads detached from the shoes and were spinning around in the drum making the noise, The drum is part of the back side of the rotor and simlar in design to standard drum brakes. The pads are not riveted, must be bonded. A new set of brake shoes is $25.00. There is an adjuster wheel, again similar to standard drum brakes, that can be accessed through a window on the back side of the hub by removing the rubber plug. Turn the wheel to allow the pads to free up a stuck rotor.