Unfortunately, you have a couple of things working against you, but the good news is, these issues are not unsurmountable. I do believe that age is an issue. It is hard to earn the respect of those older then you. Some of these guys might have been cooking while you were still peeing your pants, but with hard work, and the proper management style they will come around, but it might just take them a little while. The other big issue is your promotion. You don't know how many times I have heard, from various chefs, that the hardest thing they ever did was be promoted from cook to Sous, in the same kitchen. You have suddenly gone from being co-worker to boss, and some people resent that, and others feel they don't owe you any more respect than when you were their "buddy". Unfortunately, the best way to solve this problem is to be a hard-a**. I am not saying become a tyrant, but you really need to enforce the standards that you and chef have set. The way to earn their respect is to show them that you take your position seriously. They will push and try to get away with things just because they want to test your limits. Don't allow them to, don't let them ease up on the standards just because you are in charge, and not the chef. One of the biggest mistakes I see new sous chefs make is taking on too many tasks. It's the "I can't make them do that" or the "I can do it better myself anyway" syndrome. Work your cooks as hard as your chef does, hold them to the same standards, and don't let them pawn off their work on you. Realize that the raport you once had with your "line buddies" has changed. Yes you can still be great friends and co-workers, but now you must also be their boss, and that will change the dynamics. You will have to "ruffle a few feathers", and yes, you will p*** people off. But in the long run you will earn their respect.