It has nothing to do with CV angles. It's the shift-on-the-fly pneumatic actuator. Like you, in the winter of 1999, when my GV was brand new (and in stock form), I got it buried up to the framerails in snow. It just sat and spun, and made a banging noise in the front diff. The only thing you can do to get rid of it is get the very newest design of the differential components (a.k.a. mortgage the house for genuine Suzuki parts), or swap in the Sidekick guts and eliminate the shift-on-the-fly design. AFAIK, it's not hurting anything when it's banging, although it's definitely annoying. We're in the same boat, it appears. When we got out gearing changed, we should have eliminated the shift-on-the-fly. I planned to, but my gearing guy had short term memory, and left the GV components in. Oh well........