One problem related to noises during shifting has been reported for the 1997 Chevrolet Astro. The most recently reported issues are listed below.
After leaving a 4-lane interstate section of highway 19 in west virginia, and arriving onto a section with stoplights, the driver noticed a clunking noise while the transmission was shifting from 1st to 2nd. This occurred at multiple lights. During the occurence, the van would also lurch during the shift. We stopped at a rest area, and after allowing the van to sit for about 20 minutes, we restarted. The problem was not apparent when we left the rest area, but about 2 miles down the road, the "service engine" light came on. We drove to the nearest major city to find a dealer to look at the problem. Once we found an open dealer who could download the diagnostics, he informed us that the code indicated transmission slippage. He reset the code, and the van shifted fine. We continued to our destination without problems, and took the van to a dealer the following day. They studied the van, and determined that the valve body had failed, just out of warranty, of course. We spent $1100+ to have the valve body repaired.