Yukon Gear's rear crush sleeve is specified for 2010-and-up Toyota 8.2" applications, including FJ Cruiser and 4Runner rear differentials. As a pinion preload spacer, it ensures correct preload when servicing the 8.2" Toyota rear end. Yukon supplies a full line of differential small parts for rebuilds and maintenance, and this sleeve is intended to match the Toyota 8.2" rear differential fitment shown in the source.
Yukon Gear Crush Sleeve for Toyota 8.2in Rear