Oh, unhappy day for the Robinsons of Louisiana: Leonard Robinson's agent blubbering that the roving Truck wants traded from the New Orleans Jazz. Eddie Robinson's fabled athletic program at Grambling State put on NCAA probation for a year.

First, Grambling:

The collegiate powers-that-be came down yesterday on the rural, 4,000-enrollment institution that has become a byword as producer of countless pro football stickouts. Small cash loans to atheletes, a practice stretching from 1959 to 1977, were uncovered by a two-year NCAA investigation at Grambling, and chiefly for that, the Committee on Infractions barred the Tigers from live television in the coming season and from any postseason competition.

Eddie Robinson, the athletic director and football coach for so many years, put in, "I have nothing to be ashamed of." He admitted loans of up to $10 a month for books, fees or personal emergencies - to be repaid, at 5 percent interest . . .

Besides football stars, Grambling sent basketball a good one in Larry Wright of the Bullets, a roundabout way of getting around to Wright's erstwhile teammate here, Truck Robinson. Erstwhile because he was traded to Atlanta after complaining to the effect that Capital Centre wasn't big enough to hold both Robinson and Elvin Hayes. Now hear Robinson's attorney, Don Cronson:

"Two sets of rules . . . prevail on the Jazz. There is one set of rules for Pete Maravich, or rather no rules for Pete, and another set of rules for the other players."

So the Superdome isn't big enough to hold both Maravich and Robinson, All-Pro last season as league leader in rebounding and minutes played?

Not, says Cronson, as long as the Jazz won't renegotiate the fat, multi-year contract that lured free-agent Robinson from the Hawks a year ago. Aha.

How soon they forget. A character member of pro football's Hall of Fame passed away last weekend with hardly a notice: Earl (Dutch) Clark, 71, in Canon City, Colo. He came out of Colorado College to play quarterback for the Portsmouth (Ohio) Spartans 1931-33 and their successors, the Detroit Lions player-coach '37-38, guided the Cleveland Rams 1939-42. One of the great triple-threat backs and last of the top dropkickers.

Wilson Bell, the D.C. import from Detroit, Lost his third of 13 pro bouts in the Baltimore Civic Center feature Tuesday night. TKO'd by No. 8 junior middleweight (for the second time) in seven rounds. But Dale Staley, the Forestville Flash, stopped Floyd Pittman in three to bring his pro welter-weight record to 9-0 with eight knockouts, in the bout that most roused the house of 2,500 . . . Middleweight Irish Mike Baker, who trains at Redskin Park, got feature treatment in July's Ring mag, by local scrivener Stu Berman (collector's item, the accompanying art featured Baker flanked by "managers George Allen and Ed Williams - both smiling). Staley draws notice in the August issue of Ring . . . Staley and Bell are handled by Chris Cline - you remember him as manager of son Biff Cline. Light-heavy Biff has a bout lined up in Portland, Maine, in a few days, to end a hiatus since December. The syndicate that was going to manage him to prominence didn't pan out and Cline is working in the District Heights pizza parlor operated by his father and original manager . . .

Former pug Adrian Davis is putting on a muscular dystrophy benefit amateur-boxing show at Prince George's Community College - 10-12 bouts Friday night. Heavyweight bout pairs Tony Smith and Glen (Bull) Walls, in whose corner with Rocky and Pat Coleman will be Matt Robinson, their heavy who had to quit the ring after a household accident blinded an eye . . . Further on the Redskins and boxing: hear tell Bobby Mitchell was elected boxing chairman of the Potomac Valley AAU lately; he's also on the D.C. commission . . . Another little charitable sporting event in PG County tonight: politicos's softball at Rip's Memorial Field, Bowie, 7:30, for the county Coalition for the Support of Handicapped Children; $2 adults, under-12s free . . .

Boston Red Sox slugger Jim Rice swears Lou Graham, who played with him in the pro-am yesterday at the Pleasant Valley Classic in Sutton, Mass., hits the ball farther off the tee than anyone on the tour. Rice followed up his 26th and 27th homers the night before with birdies on the 17th and 18th for a 79. He plays to a 10 handicap with only 18 months' experience . . .

Rod Carew has really been suffering the last few weeks. Before snapping back with four hits Tuesday night, he actually dipped below A1 Oliver for the big-league batting lead, .3232 to .3231 . . .

Latest, maybe not so wild, invention on the NBA front: Knicks sign Marvin Webster, trade him to Portland for Bill Walton. Appends Webster agent Larry Fleisher: "Then what will New York give Seattle for compensation? Bill Walton?" Ha-ha.