Velvet Drive Clunks When Shifting: What It Means

1017-005 Velvet Drive Rebuilt Testing

Idle speed

That's the opposite of what a lot of people assume. A slower idle doesn't starve the pump or hurt its ability to build pressure; it's a faster idle that slams the clutch on harder. A low-rpm rattle in gear that clears up as the rpm rises is a different problem: see the next section.

Damper plate

A separate noise, a knock or rattle that only shows up at idle or low rpm and clears up once you're above about 1,000 rpm, is usually the engine or a worn damper plate rather than the shift itself. That's covered in full on damper plate noise in gear.

Cable and linkage

Binding or sticking shift linkage is on the factory's own list of harsh-engagement causes, right next to idle speed. Disconnect the cable at the transmission and move the lever by hand; if it doesn't move smoothly through both detents, that's your clunk, not the gearbox. See checking the shift cable before the transmission.

Inside the transmission

If idle speed, the cable and the damper all check out, the bang can be coming from inside the case: a sticking regulator valve, which is on the factory's harsh-engagement list too. That's a teardown, not an adjustment.

Shifting habits

Shift at the lowest rpm you can hold steady, in either order. Velvet Drive's manuals warn that shifting above about 1,000 rpm can severely damage the boat, the transmission and the engine. Chris's own rule on top of that is to take five full seconds going from forward to neutral to reverse instead of banging it in; see the five-second shifting rule.

1017-004 testing

When to call

Still getting a clunk after idle, cable and damper all check out? Call (804) 333-3677, Monday through Friday 9 to 3 Eastern, or email sales@halemarine.com.

Related reading: damper plate noise in gear, checking the shift cable and the full troubleshooting guide.