Problem final transmission!!!

[lucatnt]

Hi boys. Last night I have checked the final transmission of the xj and I have realized that turning the wheel the chain he cyclically extends, excluding the pinion because the cycle is too much along I have thought to a deformation of the crown and then I have marked the bolt in which this increase of tension is verified, however also this has not given me certainties in how much the increase of the tension is verified around every 2 turns of of the back wheel. Is it possible according to you that there am a deformation on the chain? Thanks in advance for the answers!!! :what: