rear diff lock sticking on

[Gaz]

The rear diff lock light on my cq will stay on after turning the switch off. And i have to get under the rear of the car and give the actuator a wiggle (if that's the technical term) in order to get the rear lock to disengage and the light to go out.

It seems to move a little bit on its own, but just not enough.

It also looks very oily.. Could it just need a clean? Or new vacuum lines? Or could it be the diff it self that is the problem?

Cheers.