4wd clunk every mile or so

[airhardy]

2011 2500HD Duramax.

Engaged my 4WD High on a snow covered road the other day.  Every mile or so I would hear a loud clunk.  It sounded like the front and rear driveshafts were not spinning at the same rate and popping to line up again.  It happened at any speed.  I haven't changed tires and the air pressures are the same on all 4 tires. The truck only has 70k miles.  I am frustrated with this truck.  Bought it new and always have problems.  

Thanks for your input.

[davester]

Sounds like normal binding that happens when driving on roads where all 4 wheels have good traction.

[airhardy]

Never happened before.  I have owned it since new.  The roads were snow covered and slippery,  that is what 4 HI is for.  I have driven it in these conditions many time.  It is definitely not "normal" binding.  It is very loud.

[riverbanks]

Some of the h.d.s',have the driveshaft yoke clunk like the 1/2ers,g.m. sells a synthetic lube #19257121 that's compatible with tranny fluid to lube the splines on output shaft of t.case?