Borg-Warner heavy-truck manual-transmission asbestos synchronizer blocker rings and cone friction linings (T-98, T-19, SR-4, and heavy-duty gearbox families)

Product Description

Borg-Warner Corporation, through its transmission and Warner Gear divisions, allegedly manufactured heavy-duty manual transmissions and their internal synchronizer assemblies for Class 6, 7, and 8 commercial trucks, medium-duty straight trucks, dump trucks, tow trucks, and light industrial equipment. According to publicly filed U.S. asbestos personal-injury and wrongful-death litigation, the synchronizer blocker rings inside Warner Gear T-series and SR-series heavy-truck gearboxes incorporated asbestos friction cones — either woven chrysotile-asbestos tape bonded to a brass carrier ring, or a molded chrysotile-phenolic friction wafer indexed to the ring’s cone surface — that engaged the gear speed-matching cones during shifts.

Plaintiffs allegedly identified Borg-Warner synchronizer rings in T-98, T-18, T-19, SR-4, T-88, T-89, and comparable heavy-duty gearbox families installed as original equipment in Ford, GMC, Chevrolet, Dodge, International Harvester, and Jeep truck lines through the 1980s. Publicly filed litigation records allegedly reference Warner Gear synchronizer service kits distributed through OEM truck-dealer parts networks, aftermarket transmission-parts warehouses, and independent heavy-duty drivetrain rebuild shops.

Workers Exposed

According to publicly filed U.S. asbestos litigation, workers allegedly exposed to Borg-Warner heavy-truck synchronizer-ring friction material included transmission rebuilders in independent gearbox shops, diesel mechanics performing truck-in-frame clutch and transmission service, dealership powertrain technicians, and fleet-drivetrain specialists. Plaintiffs allegedly described transmission overhauls that required disassembling the gearbox case, driving synchronizer assemblies off main-shaft splines, scraping burned or glazed friction material from used blocker rings, installing new friction rings and lightly dressing cone surfaces, and blowing gearbox internals clean with compressed air. These operations allegedly released chrysotile fibers into the shop breathing zone.

Bystander workers — parts personnel, welders, apprentices, and drivers waiting on a repair — allegedly inhaled fibers dispersed by transmission service work. Independent transmission-rebuild shops serving over-the-road fleets allegedly handled synchronizer rings on a high-turnover cycle.