One problem related to front suspension coil spring has been reported for the 2004 Ford Ranger. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Ford Ranger based on all problems reported for the 2004 Ranger.
Front suspension causes shims needed in front end alignment to wear prematurely and cause front tires to wear incorrectly on inside of front tires. Needed to get front end alignment. Ford knows about this and does warranty these part for 12,000 miles or 12 months. Spoke with Ford tech and agreed with me that this problem is not noticeable until well after that time frame.