Webb Wheel has issued updated Service Bulletin #59, covering recommended oil and grease lubrication volumes for tapered spindle (Webb part #2023) and parallel spindle (Webb part #2343) trailer hubs. The company offers optional lubrication fill plugs for most popular part numbers. Amount of lubrication required will vary depending on the hubcap, seal, and lubrication manufacturer's recommendation.
Information found in Service Bulletin #59 follows the TMC Recommended Practice RP631A, Recommendation for Wheel End Lubrication. For more details, contact Webb, Cullman AL.