My Trane (model# TUX080C942C1) direct drive frunace blower motor became hot after a few minutes of runtime. I could smell the odor of warm insulation through the register vents. The motor was running but it didn't seem to be up to speed. The squirrel cage turns freely. This unit is only 8 years old. Could the motor have gone out so soon?

Blower motors can go bad at anytime. Would suggest you get it checked out as heating up is a sign that it's going to fail shortly.

If you have a clamp on amp meter you can see how many amps the motor is drawing when the prob. Is there,, then compare to what the tag says its supposed to be drawing. If it's the factory motor you should find the info on the id plate, if not look on side of the motor

Thank you twinkiedooter and wmproop for your suggestions. It was the blower motor.
A note to all members: The OEM blower motor on some residential furnaces may be a 4 speed but your furnace usually only uses 2, one speed for heating and one for cooling.