Service Intervals
Check fluid level every 12 months or 7500 miles, whichever comes first. Transmission fluid and filter should be changed every 100,000 miles. On THM 250C transmissions, intermediate (front) band requires adjustment every 60,000 miles, or as required.
NOTE:
For heavy duty operation, transmission should be serviced (change fluid and filter or service the screen), at 15,000 mile intervals.