(FORTUNE Magazine) – WHAT DOES IT TAKE to succeed in a new job? Now that hiring and promotions are picking up again, it's worth some thought--especially since about 35% of managers who change jobs fail in their new ones and either quit or are asked to leave within 18 months, according to a new study by Right Management Consultants, a leadership-development firm based in Philadelphia. A one-in-three washout rate is pretty scary, but luckily Right's research--based on a wealth of data the firm's coaches have collected from clients since 1993--has yielded a few important pointers on how to avoid becoming a statistic. The No. 1 way to get off to a strong start: Ask your new boss exactly what's expected of you and how soon you're supposed to deliver it. "This is true even if you've worked with this person before," says Joy McGovern, a Right regional vice president in New York City who oversaw the latest study. "Expectations may have changed, so assume nothing." Many bosses, she notes, can't be relied upon to spell things out for you without prompting: "We work with lots of executives who are reluctant to be explicit about what they want. Their attitude is, 'Hey, I pay people to know that without being told!'" So ask and, if you have to, ask again.

Most managers who blow it have fine technical skills but stumble over the softer side--fitting into the culture, navigating the political landscape, and forming the kinds of friendships that help get things done. "Failure to build strong relationships and teamwork with peers and subordinates," Right's study says, is the chief culprit in 61% of new hires and promotions that don't work out. It helps to keep an eye peeled for subtle cultural signals. "Know what the taboos are," McGovern suggests. "Some organizations deal more openly with conflict than others. For instance, I've seen new executives criticized for being too direct in the feedback they give." Other clues to the culture: Will you be cast into the outer darkness if you disagree with the boss in an open forum? And how casual, or formal, is the office style? Are people's doors always open for a quick chat, or will you just annoy them if you don't call for an appointment first? Trivial, maybe, but many a career has foundered on those shoals. Another tip: Watch yourself. "Lots of people are stressed as they move into new roles," McGovern observes, "so they become more abrupt and short-tempered, or unresponsive to others." About one in five managers fail, Right's study shows, because of "difficulty managing their own behavior."

Let's say you've got the relationship stuff nailed where you are. McGovern recommends that you get busy networking all over the organization, not just in your own backyard. Find or cultivate as many allies and supporters as you can. You may need them later. At the same time, find a problem you can fix relatively easily, and fix it within 90 days. "An early win gives you a halo," McGovern says. "It's an instant boost to your credibility." And who couldn't use that?