dryer runs for 5 min then shuts off

dryer starts, the drum is turning, and it gets hot. after five minutes dryer cuts off. it will start right back up then cuts off in about 5 minutes. unit is clean and exhaust line is clear. how can I fix?

Its very likely the motor is bad and overheating. Here is the part you will need.
http://www.appliancepartspros.com/ge-kit-motor-and-we17x22217-ap5958529.html

When I Run The Dryer In The Cool Down Mode (no Heat) It Does Not Cut Off. Would It Still Be The Motor?

How long will it run in that mode?

dryer runs full cycle ( 20 min)

No if it only shuts down in heat mode then the motor is likely ok.
Have you tried in other modes like delicate mode (low heat)?
It may be a problem with the control board.
http://www.appliancepartspros.com/ge-electronic-board-we4m296-ap3423314.html
I doubt its an issue with the thermostats as they only shut down the heat not turn off the dryer.
Its not the thermal fuse it doesn’t reset.

yes, in all heat modes it shuts off.

I would be inclined to say the control board is having power issues. Try replacing it.