Our 1997 Dodge van has a vibration when you accellerate. It started when you would be pulling a hill, but has started happening more often as of late. It was suggested by a friend that it could be the front axles? Any suggestions? Also the check engine light just came on at 169,000 miles.

Did the vibration problem start about the same time as the Check Engine Light?
When was the last time you had plugs and wires? How about transmission fluid/filter? Start with the code for now. Also, your friend may not be that far off.
Here is a link with info for retrieving the codes
http://www.allpar.com/fix/codes.html