105 series won’t turn all the way lock to lock

[boilylyfe]

So I was on the tracks on Boxing Day and suddenly couldn’t turn. Backed up a bit still could barely turn like it was a full lock but wheels were just off straight, 6 point turn to turn around and then could turn full lock. Get home and try again same thing. Couldn’t turn fully but if I wiggled it, it would eventually get to full lock. Steering pump? Steering box or possibly something in swivel hub is what I’m thinking. TIA