Don't rely on the manufacturer's recommendation. Pull the hub/drum off and measure the seal and spindle with a digital caliper. Not only did my 9100 pound 5th wheel come with the wrong "oil seal" as they're called at the parts store, but AL-KO took my Axle serial number and still sent seals that were 4.5mm too large. No wonder they leaked. If you've got 7K AL-KO axles on a FR product chances are good that a Napa oil seal part # 21352 will help.
1999 F250 w/7.3L Diesel
2014 Silhouette 299RKDS
Nights Camped 2016 - 21
He who dies with the most tools, wins!