4 Wheel Drive/SUVs: astro van awd, cv joints, slip yoke

Question
i get a loud clunk from underneath the van under hard acceleration or even holding the brake in and pressing the gas. no bolts are broke and all mounts are ok. it sounds like something is binding up in the front axle or the transfer case. do you know of any common problems such as this on awd or 4 wd.

Answer
Mark,

This can be a hard one to diagnose without, actually driving the van.  I would suggest that you start by double checking your motor, and transmission mounts.  Another possibility, is a bad universal joint on the front, or rear drive line.  I have seen the slip yoke on drive lines bind, and make this sound when they free up.  If these items check out ok, then check out the front axles, and the cv joints.  If you can't isolate the problem, see if you can find a reputable shop that can check this out for you.  Many shops will give you a free estimate, or at the least an idea of the source of the problem.

Carl