After some problems with the original locks on the van (they’re the old key type, not the newer ‘standard’ hexagonal Ford key), I decided that replacements were needed. I ordered a lockset for the Mk4/5 Transit (the standard hexagonal key) and crossed my fingers that the locks would fit.
The ignition barrel was a straight swap – nice and easy.
The door locks, however, needed the doors filing a little to accommodate the square shape of the new lock barrels.
Other than that, the inside part of the lock is a straight swap, just undo the locking rod from the old lock, and re-attach to the new lock. I needed to adjust the lock retaining clips to hold the lock in position – this is a simple as bending the legs out a bit and then squeezing it back in place. For the front doors you will need to undo the window carrier strip (torx screw) to get enough room to do it.
Then remember, a little bit of clean engine oil on the key, put in the lock and wiggle around, to keep it nicely lubricated (the locks come pre-greased, but this is a good maintenance check).