I would go over the rig and look for fluid leaks in the shocks and differentials. I would tighten all the screws and nuts and use LocTite on all metal-to-metal connections. Make sure to use a medium strength version such as the Blue #242 or 244 (the stick form).
Use loctite on metal to metal screws and I would highly recommend the Blue Loctite Stick - no drips, doesn't dry out, easy to apply, and one stick will last you a long long time.
I've had issues with the LocTite stick not holding as well so I've went back to the liquid myself. Maybe I got a bad stick, but either way, back to what worked for me.