There is a seal between the motor shaft and the pump housing, below the drain impeller. If it has failed it would cause leaking onto the motor. Whether it is the cause in your case, I couldn't say from here.
You can see an exploded parts view of your model at the following link.
LINK >
Maytag DWU8402AAE Exploded Parts Views
If that seal is indeed needed, the other mating half and possibly the drain impeller too should usually be replaced at the same time to ensure a proper seal. All those items plus the pump housing gasket and instructions are also available in a single kit if needed. Servicing the pump is usually done from inside the tub.
LINK >
Maytag DWU8402AAE Pump Impeller and Seal Kit
JMO
Dan O.
www.Appliance411.com
The Appliance Information Site
=D~~~~~~