Very rusty rear axle on Ford transit

[bongoboy]

I have seen a nice Ford transit van that i'm thinking of buying.
The only fault i can find (if you can call it that) is that it has a very rusty rear axle.
I know they can get rusty as they are underneath and exposed to the elements, but this ones very rusty.
Is this a concern or would it cause no problems as i asume the axle is thick heavy metal and therefore the rust would onlt affect the casing surface.

[bongoboy]

I should add that the rust is on the middle casing where the oil goes.

[beso]

Can be a good thing in itself if not too bad as it means there are no oil leaks in the diff.

However it sounds quite severe from your description so is probably affected by salt. This may indicate the vehicle has been exposed to a lot of salt and suggests the body could be similarly corroded.

Have a very good look at the sills and make sure they are not bogged with body filler. If the paint is not original I would be very suspicious.