Carl Tuveson has documented a factory error in the construction
of the power trucks on the GP engines, and an easy solution. The problem is
detailed here - more information is available at the S-List
Files Section.
Most of the Lionel-American Flyer Geep and EP-5 series engines
have what I consider a defect in the assembly of the power truck. The wheel-axle
assemblies of the power truck are switched front to rear. The traction tire
wheel should be next to the truck side-frame power pickup. Not all of the trucks
were assembled with this defect, but most were. The only one I have that was
correctly built from the factory was the 370 GM demonstrator re-issue. By
switching the axles from front to rear in the power truck frame it will spread
the trucks ability to pickup power over switch frogs and crossovers and greatly
improve performance.
Picture #1 The side frames with pickup shoes. The correct assembly is on the right.
Notice the distance between the steel wheel and the sliding pickup shoe (marked
in red). The longer distance allows continuous pickup through crossovers and
switches.
Picture #2 The correctly built truck on the left and the defective assembly on the
right. The traction tires are removed in all of these pictures for clarity
Picture #3 Switch (exchange) the un-insulated wheel/axle assemblies. The left with the
right in the picture.
Picture #4 This shows a simple tool made from 1/8 in. aluminum stock used to center the
gear back on the axle.
Picture #1
Picture #2
Picture #3
Picture #4