Cause of grabbing brakes

[Ian Williams]

With that amount of force it is likely that the end of the radius arm which houses the brass cups has been spread allowing the cup to move within the arm. No matter how tight the centre bolt is done up movement will still be present under braking, get your friend to remove the arm's and check the fit of the brass cups, if this is the problem I would expect it to cause worse grabbing in reverse though. It seems obvious that something related to the accident has caused the problem, what else has been changed to repair the damage, to break a king pin and radius arm ball other components must have been damaged, axle, stub axle crossmember, steering and track rod arms? Is the new king pin a good fit in the axle, with that amount of force I would expect the eye would be spread and axle possibly bent.