Join Date: Sep 2010
Location: Salt Lake City, UT
Clicking noise solution...
I hope this helps...
My 2007 420 SRA was doing the exact same thing. Clicking/popping noises from the rear end.
I figured the bearings were bad due to the so called defective seal on the rear end. Since I had bought it used, and had obviously been thru mud, I figured that was the issue. I bought the new side bearing and seals and fluid online and started disassembling. Wasn't a bad job, but in the dissassembly noticed that the big nut on the left side of the axle, that tightens against that tube that goes over the axle a little bit on that side, wasn't very tight. I went ahead and changed out the parts, noting that the fluid was still clean, and the seals and bearing did not look bad.
Sure enough that solved my problem, but just as an experiment I loosened that big axle nut...and the clicking came back! Tightening it went away.
Long story short, I probably could have just tightened that big axle nut on left side and would have been fine, but at least now I know that the bearings/seals/fluid is all good.
Try tightening that nut and see what happens. (Not the WHEEL nut, there is an AXLE nut on the LEFT side, on the left side of the tube that butts against the rear diff gear.
Hope this helps!