# Clean & Adjust Chain

The chain is a safety-critical component. A broken chain at speed can cause catastrophic mechanical damage to the engine and drivetrain. See [Chain Guards and Replacement](https://manual.rush.sr/tunables/chain-guards-and-replacement) for background on why this matters.

For per-session lubing and detailed inspection, see [Lubing Chain](https://manual.rush.sr/maintenance/maintenance-schedule/each-session/lubing-chain). This page covers the deeper cleaning and adjustment done on a weekend cadence.

## Cleaning

1. Elevate and support the rear of the car so the wheels can spin freely.
2. Apply a naphtha-based chain cleaner (Maxima CS75920 or similar) while slowly rotating the wheels.
3. Scrub with a chain brush to remove dirt and old wax buildup. Clean the sprockets too.
4. Let the cleaner evaporate completely — do **not** re-lube a wet chain.
5. Apply Maxima Chain Wax evenly while rotating the wheels.

{% hint style="danger" %}
Never use a general-purpose solvent or WD-40 as a chain lubricant. Use dedicated chain wax only.
{% endhint %}

## Adjusting

**Spec:** ½" to 1" (12–25 mm) of vertical play at the midpoint between the engine sprocket and the differential sprocket, measured on the slack (bottom) side with the car on the ground.

The Rush SR adjusts chain tension by repositioning the **differential**, not a wheel. The chain tensioner is a pair of double-female threaded adapters — one on each side of the differential mounting — that screw inward or outward to move the differential forward or rearward.

1. Check chain slack at several points through the chain's rotation by spinning the wheels. The tightest point in the rotation is what matters — **a tight spot anywhere is a problem**, not something to adjust around.
2. If adjustment is needed, turn both chain tensioner adapters equally — inward to increase tension, outward to reduce it. Keep both sides matched to maintain differential alignment.
3. Re-check slack after adjustment and verify it is within spec at the tightest point.

{% hint style="info" %}
A new chain will stretch and need adjustment several times during its first few hours of use.
{% endhint %}

{% hint style="danger" %}
Use only **RK GXW 530** chain with a rivet link. No substitutes. Approximately 64 links.
{% endhint %}