2.5di camshaft end float measurements

[In-transit]

Hi All.
Had a cambelt snap and whilst stripping engine to do that thought I'd thought I'd change the camshaft oil seal as it's leaked for 2yrs! Once I'd taken off cam pulley I (Don't know why but I did) gave the camshaft a pull with my fingers and it moved out 3/4mm! Went back in luckily but leaves me wondering
a)why the thrust plate let's it move so much. Can't inspect thrust plate as it's behind the engine front plate (intermediate plate in manual) and that's not off. Should camshafts move that much?
b) can I change oil seal from the front? manual says to remove engine front plate and remove from rear of plate but I'd rather not have to get gasket or take off more components
c) can oil seal be changed with camshaft in situ?
Many Thanks All

[dumper]

It’s a very long time since I stripped a di but the part you pulled maybe a loose seal runner that the seal runs on and you can pull it off to remove the seal and then fit new seal and refit it if it has a grove worn in it is a replaceable part you should be able to see that it slides on to the same key way and key that cam wheel locates on hopefully someone who has stripped one more recently can confirm

[V184]

Yes there is movement & you can change the seal in situ but it must be 100% straight otherwise they leak

[In-transit]

Thanks for that, what a relief.