By the Rhodex RC Line product team (IGNIS Overseas Ltd, Isleworth, UK). Claims reviewed by IGNIS Product & Compliance on 14 Nov 2026. Last updated: 14 November 2026.
Short answer. Start from the diff oil weight in your car's manual or setup sheet. Rhodex RC Line Silicone Differential Oil is graded in cSt: thicker oil makes the diff act more like a spool (more drive, less turn-in); thinner oil lets it differentiate more. Change one diff at a time.
Key facts
- Product: Rhodex RC Line Silicone Differential Oil
- What it is: Silicone differential oil, sold by viscosity grade (cSt)
- Made for: RC gear differentials
- Not for: Shocks; ball differentials (use Ball Diff Grease)
- Who makes it: Rhodex is a brand of IGNIS Overseas Ltd, Isleworth, UK
How to do it
- Check the manual's starting weight.
- Drain and clean the diff.
- Fill to the level the manual shows.
- Reassemble; check for leaks.
- Test; adjust one diff at a time.
When to choose something else
- Ball diffs: Ball Diff Grease.
- Three-weight comparison: Diff Oil Tuning Set.
Common mistakes
- Over-filling, which pushes oil past seals.
- Changing front, centre and rear together.
FAQ
Which end first? Many tuners start with the centre diff on 4WD cars.
Sources
Your equipment maker's manual