Outer Limits 4x4 Board

ive had me gq for about 3 months and its started making a rattling sound like a loose washer or spring and sounds like its coming from around the diff so ive checkd all the visible bolts n spring but there fine im running 35s has anyone else had this problem

Check for cracked/loose brake backing plates where they screw on to the caliper bracket. Also check where the spring mounts to the axle case for cracking. Could also be wheel bearings requiring grease..

Nick