Call DTT
Wstow, go through the links section and call Bill K. at Diesel Trans. Tech. I just cracked one on my 1 ton.
If I remember correctly he stated that if it isn't cleaned properly when the new plate is installed it will crack again.
It seemed logical to me that as the plate flexes debris can get caught behind it and crack it. This is more than likely what happened to mine. I've been running a lot of gravel roads w/o the dust cover on the bottom of the transmission. The tech at our "great" dodge dealership that installed the new transmission said it wouldn't hurt anything to run w/o it.
Call Bill K. !!!