As of 2019 we have found Rover had changed supplier of their knuckle joints and no longer fitted this correct shaped cup with a flat pointed base, but still supplied this original cup as their 21A423 but at a higher price.

However we recommend fitting these correct types when possible as any sediment or debris gets pushed to the bottom leaving the cup sitting high, which can change ride height and encourages wear as the ball of the pin eventually pushes through the nylon.

This cap ensures the joint sits firm in upper arm location which have a hole in.