i took my car out the other day and i went to go flat out and it just stoped and the motor span and so did the pinion and spur gear but the wheels didnt

im not sure if its the diff or what
its not the arm things (thats my echnical term

) that go from the wheel to the diff or the sliper clutch so it must be the diff.
tell me what you think and a uk website wer i could get the new parts.
chris