Gary
If you are still wanting to rebuild your 8111 DT&I Switcher here are the part numbers you were looking for.
Parts for Diesel Switcher with manual or 2 position reverse
Complete Motor Truck =#8010-100
2 position E-Unit = #102-1
Commutator brushes = #8040-150
Drive Gear = #8010-116
Pinion Gear (2X) = #8010-117
Worm Wheel = #8010-115
Axle Bearings = #8010-118
Hope this helps