Lubrication - Service Intervals
WARNING: This page does not describe the selected car, but rather 16 other vehicles, including the 1990 Plymouth Sundance, 1990 Plymouth Laser, 1990 Plymouth Horizon, 1990 Plymouth Acclaim, and 1990 Eagle Talon. However, it is still accessible from the selected car via links, so may be relevant.
Check fluid level whenever performing other underhood services. Draining, refilling and band adjustments are not required under normal driving conditions. Under heavy duty (severe service) conditions, change fluid, replace filter, and adjust bands (if applicable) every 15,000 miles. On ZF 4HP-18 units, the transaxle fluid and filter screen should be changed every 30,000 miles but, while the differential must be checked, the fluid need not be replaced.