Is there a limit for how much older or younger a bride an groom can be? There some very old men who get married to very young girls, Is this haram?
Also is there any recomondation of the age difference between a bride and groom?
There's no age difference recommended in the shariah. Only thing that's obligated is that the marriage must be done properly with the consent of the two individuals.
The issue of age old and young is a cultural matter and not religious.
As long as both are willing to marry (both should be adult) then no one can have any issues with it. its just people, who have made this issue a fuss that why old men marry young girls. If both have no issue with marriage, then its perfectly fine. its not haram or prohibited in any way.
Islam didn't recommend any fixed age difference for marriage. These limits are set by our society : as in most of the society the groom seems to be older than the bride, it happens since females tends to be more depended on male on financial issues in most countries..
But yes both should be adult, and since its a very important part of our life, so we tend to do this at our mature age to take the right decision..and to understand that which will be good for both sides. So, yes.. both should be adult for this reason.