Dale, years back did same in a Mk3 Cortina (Aussie 6 model) with a 289 in it, on motorway in 4th, drizzle, driver feeds in right hand peddle and slowly start putting on left lock as back slids to inside of camber. This was common. They actually were not too bad in dry with high pressure. Square shoulder buggered them.

How many times you replace rear axles in Mk1 Dale.