Undated (AP) _ The Cleveland Browns learned the dangers of standing still in 1981, when they followed their 1980 AFC Central Division championship with an embarrassing 5-11 record.

So off a 12-4 season that came with 37 seconds of the Super Bowl, owner Art Modell can't be accused of standing still, although the wisdom of his biggest off-season move remains to be seen. The Browns sent Pro Bowl linebacker Chip Banks to the San Diego Chargers last spring and have replaced him with rookie Mike Junkin of Duke, their No. 1 draft pick.

Coach Marty Schottenheimer has been open in his admiration of Junkin's college performance, but a two-week holdout at the start of training camp put a dent in Junkin's plan to step directly into the starting lineup.

''He reminds me of the way (former Pittsburgh Steelers All Pro) Jack Lambert played,'' Schottenheimer said. ''Now, you've got to remember, Mike was at Duke, and the other guy is on his way to the Hall of Fame.''

If Junkin can take over where Banks left off, the Browns should be favored to win their third straight AFC Central Division title. The division became a two-team race between the Browns and Cincinnati Bengals a year ago, and it should be the same in 1987.

''The main thing for us to remember is there are a lot of important games for us to play between now and our goal, which is the Super Bowl,'' said Browns quarterback Bernie Kosar.

Cleveland's regular-season success was somewhat lost in the drama of its two overtime playoff games last year - a 23-20 victory over the New York Jets and the 23-20 loss to the Denver Broncos in which the Broncos tied the score with 37 seconds left in regulation after a 98-yard scoring drive directed by John Elway.

So the Browns must fight the tendency to overlook the task of winning their division, which wasn't as easy as it might have seemed in 1986.

Cleveland was 5-1 in the division, splitting with Cincinnati and beating Houston and Pittsburgh twice each. But all four games against the Oilers and Steelers were close, and two went into overtime.

''I think there are three teams from this division that could be in the playoffs,'' said Cleveland's 10th-year tight end, Ozzie Newsome, omitting only Houston.

The 23-year-old Kosar is the key to the Cleveland offense. He passed for 3,854 yards while throwing just 10 interceptions.

Cleveland's running game, one of the league's best in 1985, suffered in 1986 because of injuries to backs Kevin Mack and Earnest Byner and because of the passing offense installed by offensive coordinator Lindy Infante. That option-filled system got off to a slow start, but Kosar felt comfortable with it by year's end.

''It's the second year with the same system and really the first time in about five or six years that the Browns have had the same system back to back, so it'll help all of us,'' Kosar said.

The Browns' respectable defense, built on the man-to-man coverage of cornerbacks Hanford Dixon and Frank Minnifield, might make the difference in the divisional battles with Cincinnati, whose offense was the best in the NFL a year ago.

The offense was so good that Coach Sam Wyche sees no reason they cannot improve on their 10-6 mark, which left them a tiebreaker shy of making the playoffs in 1986. But the defense gave up 394 points, by far the worst in the division.

''They (the Browns) talk a good game,'' Wyche said. ''We decided among ourselves that we're going to celebrate after the season.''

Quarterback Boomer Esiason passed for 3,959 yards and 24 touchdowns last year and has two of the best receivers in the league in Cris Collinsworth and Eddie Brown. Pro Bowl back James Brooks averaged 5.3 yards per carry and finished with 1,087 yards rushing and another 686 yards receiving.

No. 1 draft pick Jason Buck, who was expected to step right in an improve the pass rush, is a holdout, so defensive line coach Bill Urbanik is teaching his linemen karate techniques to improve their pass rush.

''It's body mechanics and body usage,'' Urbanik said. ''We're not kicking anybody.''

The Steelers' 1986 season was wrecked by a 1-6 start, and they finished at 6-10.

''The strength of the team right now is probably the rushing game. We have Earnest Jackson and Walter Abercrombie. They ranked third and fourth respectively in the conference rushing,'' team spokesman Dan Edwards said.

Mark Malone returns for his third year as Pittsburgh's starting quarterback after a poor 1986 during which he passed for 2,444 yards with 18 interceptions. The Steeler passing game ranked last in the AFC as Coach Chuck Noll's team tumbled to its worst record since 1970.

The Steelers' hopes of rebounding this year suffered a blow when their top draft pick, cornerback Rod Woodson of Purdue, announced he was bypassing the team's contract offer to try out for the 1988 Olympics as a hurdler, although he may yet sign at some point.

The Oilers, 5-11 last year, are surprisingly confident for a team that has the worst overall record in the NFL the past five years.

The reason? Coach Jerry Glanville revised his offense late in the year, and quarterback Warren Moon began to resemble the player he was in the Canadian Football League, leading Houston to four victories in the last six games he started.

''I think a lot of people criticized Warren last year in situations where it was not his fault,'' Glanville said. ''I still believe he has one of the strongest arms in the league.''

The Oilers' offense has been set back by the holdouts of veteran offensive tackle Bruce Matthews and first-round draft pick, fullback Alonzo Highsmith.

On defense, the Houston pass rush was weak. Ray Childress led the Oilers with five sacks.

''If Ray can take just one more step towards improvement, the Oilers are going to have a real good football player,'' Glanville said.

Running back Mike Rozier, a disappointment in his two years with the Oilers, has his own plan for turning things around in Houston. He's switched his jersey number from 33 to 30 - the number he wore when he won the Heisman Trophy at Nebraska.