not sure what the problem is but it shudders and clunks I'm getting concerned it has 42k on it and I just got new Goodyear MTR's......... any ideas?

 

not the best news, but I just spent 1909.00 on a tranny rebuild for a 4r70w. Mine did the same before it went. May not be your case but it was mine. I HIGHLY recommend taking it to a tranny shop immediately, so they can diagnose your problem. At first, all I had was a bad pressure solenoid, after driving it, I broke all sorts of interesting components.