We have been having trouble with a Dexter Dryer Hi Temp limit and after trying a few repairs I talked to a Dexter Service Rep and he explained it could be a problem with the internal re-circulation duct.
I gave the drum a push to turn it and it would barely move. After changing my angle a little it finally gave way but was still very difficult. After a few tries something came loose and the drum turned. Then I noticed something fall into the lint screen.