[b]C Class seat back mechanism[/b]

[PaulC]

I am having a problem with the rotary knob mechanism that tilts the seat back from an upright to reclined position.

The mechanism is turning to recline the seat, but seems totally jammed when I try to bring it to an upright position. I have opened the seat but the mechanism looks to be a sealed unit.

Has anyone had experience of this before and found a solution??