After watching the video again, I agree with JDaddy. We've discussed this before. The problem is axle gauging and the mesh of the spur gears on the outside of the truck.
https://ogrforum.ogaugerr.com/...-lionel-service-dept
Mr. Garcia might be a candidate for the "bread clip mod," but the real solution would be a new truck block from Lionel with properly gauged axles, and spur gears that don't wobble excessively on their studs.