I serviced four StarTrac 5631 Series Treadmills for the Berwick Academy in South Berwick, Maine. These were donated from a fitness center. As is the case with many fitness centers the equipment is not well maintained.
All four treadmills needed new deck surfaces and new tread belts. Two of the treadmills needed new front roller bearings. One of them needed to have the motor repaired.
I was able to flip the decks on three of them. One of them needed the deck replaced since it had already been flipped previously.
Since these were donated treadmills we scrapped the one that needed new front roller bearings as well a new or rebuilt motor. The cost of the repairs exceeded the value of the treadmill.
Fortunately they already had a Precor treadmill and someone else donated a very nice LifeFitness Treadmill, so they still retained five treadmills.
I did end up replacing the front roller bearings on one of the StarTrac machines, which is much less expensive than replacing the roller. Actually due to the age of the treadmill these StarTrac rollers are probably obsolete.