This dryer is less than 6 years old and lightly used. After running 5 min on auto dry, the top gets very hot and the dryer shuts off. After 10 mins. it can be restarted and completes the cycle normally, with cooldown. On restart, timer advances normally and the top remains cool.

Also shuts off on timed dry, after a longer time
Disconnecting from exhaust ducting makes no difference
Internal air passages were cleaned and vacuumed
Exhaust air flow seems normal
Motor was pristine clean; does not hum or growl
Drum rotation does not drag, no noises
Fan is secure on shaft
T-stat on blower housing has been replaced
No air blockage around dryer, not in a new location.

Suggestions appreciated. Thanks.

Still having a problem. Verified that the blower is secure on the shaft. Heaters are not grounded.

When I replaced the operating T-stat, it moved and left a small air leak. Re-seated it and the dryer runs longer before overheating. Also shifted the felt seal to cover a small gap at one end. Now the timer advances on a small load, but less than half as much as it should. Clothes are already dry and the timer has a long way to go. At least not shutting down on overheat.

To recap, ducting is perfectly clean (vacuumed) and for testing, discharging right into the room. Air flow seems normal. Motor was never dirty, looks new. I'm thinking the blower is sucking cool air, but all gaskets look fine.