Anyone in South Wales needing to have their's tested there is a company in Neath called BAR Propshafts who will test your unit, if you remove it it will save you money on them doing it. A replacement reconditioned unit is just over £200. If you need a new unit they will test that one to before fitting it.
This is a repeatable company that has been going as long as I can remember and the company I work for has never had a problem with their items.
Abbey Road Industrial Estate, Neath SA10 7DN
01639 646922