The Yokomo RP-113375 RP Ultra Shock Oil #37.5 is supplied as a silicone-based fluid in a 40cc bottle and marked purple for identification. The RP Ultra series was reworked to provide closer viscosity steps to help tuners achieve targeted damping without changing mechanical parts.
As a dedicated shock fluid it controls piston flow and rebound rates inside R/C shocks. Apply it when tuning compressive and rebound behaviour to get repeatable results; the purple colour makes it simple to tell this 37.5wt bottle apart on a cluttered bench.
Installation on typical threaded shock bodies is direct: empty the old oil, clean the internals, refill to the recommended level for your shock, then cycle the shock several times to purge air and seat the piston. For consistent setups use the same filling technique and inspect for foam before finishing assembly.
Copyright © 2008-2026 rcjaz.com.au All rights reserved