I have some Plus F7s that I have painted up for Milwaukee road. I have converted then to dummies ( white cracked gears ) except for one F7A that is the older nonDCC spectrum with black gears.I have thought of ordering some replacement wheel sets from Bachmann to power some B units. My question is the photos of the new replacement axles show white gears. Is this a older photo or is it a new plastic that does not crack ?