Worm and ball bearing nut steering

this type of gear box can be seen on tata vehicle  

in this type of  steering arm In front of   on the worm  one nut stays 

 But nut and worm. His in the throat  Eistil ball stays ball   Nut should not get out of the throat  for this   

  his side two     TransFer   Guide by putting   With the help of lock nut Does lock

  At the time Worm is rotated  From side of the steering wheel         At that time Worm steel ball by transfer guide nut of one side to other side it happens rotated  And nut also being up and down  With them Cross shaft and  His with attached out side drop arm  Also revolves with and worm his inside stays ball  Number of steel ball as 78 So stays   and for Adjust end ply set Worm side  on  bottom cover  adjesting nut his with lock nut stays fit