Back in 2018, Gale Banks stood beneath a Ford F-150 Harley Davidson edition with a clear plastic differential cover bolted to the axle housing churning up full-synthetic lube-like cake batter. He had just begun his investigation into aftermarket rear differential covers. “Do they actually do something or are they just bling?” he pondered. Based on decades of mastering fluid dynamics, Gale surmised that stock covers were curved for a reason. A diff cover with a flat backside will destroy and lubricant, he told the audience. But how would he show what was going on behind that steel cover? A clear plastic diff cover.
Not long after posting the video above, Car & Driver, Road & Track, Jalopnik, and other popular automotive outlets shared it. But what many viewers of this four-year-old video didn’t know at the time, is that Gale would go on to solve the cooling issues caused by then-popular flatback covers. He’d invent and patent his own, one that would make all other aftermarket covers obsolete… the Banks Ram-Air Diff Cover.