Yokomo YOKB2-S4B Replacement Lower Shock Cap  [YOKB2-S4B]

This lower shock cap is designed as a straightforward replacement for the bottom closure of RC dampers, focusing on reliable sealing, oil retention, and stable support for the shock shaft and internals during maintenance and rebuilds.

To fit: remove the shock from your model, drain oil if present, disassemble the lower end, exchange the original cap for this replacement, then rebuild using the original internals and oil grade. Confirm shaft runout and piston movement are free before refitting to the chassis.

In workshop practice the lower cap affects leak prevention and serviceability more than suspension dynamics. Include O-ring and seal checks in your maintenance plan, ensure mating faces are clean, and verify correct thread engagement to reduce the risk of cross-threading on assembly.

Hobby note: this item is intended for RC-scale damper servicing on model cars only. Keep spare seals and a small parts tray handy to make repeated rebuilds quicker and neater.