Having problems identifiing noise comming from rear of my 74' 260. Replaced carrier bearings and checked wheel bearings for play. They seem to be ok. Noise is not consistant but is very loud. I can't detect any pattern. Comes and goes at all speeds, steering straight and turning. Accelerating and decelerating. All u-joints seem to be ok also. Could it be the splines in the half shafts?