Chevrolet Repair: 2002 Astro AWD Transmission, noise vibration, slipping transmission

Question
This year I bought a 2002 Astro AWD that had previously been in a front-end collision.  The van made a grinding noise/vibration in the front end when I would drive (noise most noticeable when just starting out but could still hear it when driving - feel the vibration through the gas pedal).  The salesman actually heard this with me on the test drive, but neither of the mechanics could (allegedly) recreate it.  The noise is NOT the noise/vibration that the ABS makes when starting.  I am now noticing that the transmission feels like it is starting to slip and am curious if this noise/vibration could be an issue with the transfer case?  Would having the transmission fluids flushed/replaced help the slipping transmission? Thanks!

Answer
Hi Gayle, This is a hard one for me to answer without driving the van. If it happens going straight down the road the transfer case is not the problem. First thing to check is the TIRES. They need to be all the same MAKE,AGE, and size. The front can't be worn more then the rear, or one tire worn more then another.

Let me know from here

Have a Great Day     Mark