The concept of teamwork only works when all team members do. If yours won't, you may have to force the issue
My boss is crazy about teams. Everyone in our department is teamed up with someone else, and we live or die by our team-of-two results. I had a fantastic teammate for four years, but he left to go to another division of our company three months ago. My new teammate is very good in front of customers, but otherwise he does little to no work. I pick up the slack, because our team results are what I'm evaluated on. And when I've spoken to my teammate about the problem, he says, "I'm the front man, and you're the back-end guy." I am tired of doing literally all the work on our customer projects and being seen as my slacker teammate's first mate. I am pretty certain that my boss will not want to hear from me about my team problem, because he (my boss) believes that working through team issues is part of our responsibilities. I could use some advice.
I am sympathetic—my friend Jennifer got mixed up in one of these situations in graduate school and had a class grade that was completely dependent on a team project, but poor Jennifer's teammate did nothing. Jennifer ended up doing all the work just to save her own grade. And in these situations, you can't call your teammate's bluff by dropping the ball on a few projects, because if you do, your own evaluations will suffer (and your customers will suffer, too).
If your boss wants you to handle your team issues on your own, and you've tried problem-solving with your teammate to no avail, you're going to have to adjust the relationship yourself. I would sit down again with your teammate (call him Jason) and say, "I can see that you like to be the front-end guy, but I want to and need to have client contact, too." You can push back against your teammate's division of labor on the team—his scheme where he's the client-facing guy and you're the poor schmo in the back office—and get more involved in the face-to-face client issues yourself.
You can insert yourself into more of the day-to-day client interface and then make sure that your own, personal commitments to your customers are met. That way, you and your teammate will each have individual obligations to your customers, and you can make sure that you, personally, haven't let any balls drop. Then, when Jason's client obligations begin to be late or missed entirely, you can pick up the slack, but with the understanding that you're helping him out, not serving as the do-everything guy for your team of two.
You'll want to begin asserting yourself in meetings, saying things like, "So then I'll do the marketing projection and have that to you on Friday, and Jason will get you the slides by—did you say Tuesday, Jason?" You can follow up these meetings with e-mail confirmations so that everyone is clear who's doing what, and by when. I am sure you'll be happy to help Jason with his deliverables when the team's reputation and the company's client relationships are at stake. But you'll make sure that everyone, including Jason, is clear that you're pitching in to help your buddy, not shouldering the burden for both of you because Jason appointed himself top banana. Best of luck to you.