Nobody Knows the Troubles He’s Seen : CADILLAC JUKEBOX.<i> By James Lee Burke (Hyperion: $22.95, 297 pp.)</i>

The great mystery writer Rex Stout once told me that a contemporary of his, Dorothy L. Sayers, grew so disgusted with her creation, Lord Peter Wimsey, that she became physically ill if anyone mentioned him. Sir Arthur Conan Doyle was so fed up with Sherlock Holmes after just two novels and 24 short stories that he tried to retire him permanently. James Bond made it through five books before Ian Fleming tried to bump him off. I don’t know how James Lee Burke feels about his series protagonist Dave Robicheaux, but after reading “Cadillac Jukebox,” his ninth search for justice in the backwaters of Louisiana, I’ve had my fill of the morose, self-righteous son of a gun. At least for a while.

Actually, a newcomer to Burke and Robicheaux may find “Jukebox” a compelling and suspenseful book, several notches above the average mystery. The author’s sense of place, the Louisiana bayou country, is as vivid and complete as anything Raymond Chandler ever wrote about Southern California. His style is smooth and seemingly effortless. And the plot, emanating from the decade-old assassination of an NAACP leader, is satisfying enough.

But for the reader who is familiar with Robicheaux’s past troubles and travails, Burke’s main competition is himself. And that’s where the new novel comes up short. It’s neither as unique and suspenseful as the early books, “The Neon Rain” and “Heaven’s Prisoners” (the basis for an underrated current film) nor as downright brilliant as 1991’s “Black Cherry Blues,” arguably one of the best crime novels of the past decade. Not only does it add nothing new to the distinguished series, its superfluity seems to underscore its hero’s unremitting depression.

Robicheaux has the right to sing the blues, of course. As Burke would have it, he is a recovering alcoholic whose first wife and several girlfriends have perished at the hands of homicidal fiends. (Mystery fans may recognize this as the Travis McGee Syndrome: To be loved by the hero is to court a swift death.) Not only does he suffer the pangs of guilt and personal loss, he has to stand by helplessly, as an honorable lawman, while crass, wealthy spoilers wheel and deal and good folks die like dogs.

In “Jukebox,” despondent Dave seriously rains on just about everybody’s parade--from his wife, Bitsy, who’s having a hard time living with a candidate for sainthood, to an assortment of crooks, big time and petty, who don’t understand his staunch moral code, to the state’s governor elect, Buford LaRose, and his wife, Karyn, who resent his holier-than-thou attitude, among other things. Dave and Karyn were an item back when he was in his good-ol’-boy drunk-and-debauched stage, and she can’t quite get it in her head that he’s changed. “You’re a pill,” she finally says, pegging him. Buford, meanwhile, whose political fortune somehow hangs on a book he has written about the assassination of the NAACP leader, gets downright grumpy when Dave solemnly suggests that the tome contains errors, like the wrong murderer. Even Robicheaux’s boss, the New Iberia sheriff, who treats him with avuncular affection, is moved by one of his dreary pronunciamentos to reply with heavy sarcasm, “God, you’re a source of comfort.”

There are signs in “Jukebox” that Burke may be wearying of his hero. Two sections of the novel are presented in a voice other than narrator Dave’s. Several plot elements from previous books are given a reprise--the good-bad chum out of Robicheaux’s past who risks death by walking a tightrope between cops and crooks (see “Black Cherry Blues” and “Burning Angel”), the movie company on location (“In the Electric Mist With Confederate Dead”) and the smarmy politician with more skeletons in his closet than John Wayne Gacy (“A Stained White Radiance”).

There’s a barely intelligible rumination on prison life that serves no obvious purpose, except to display the author’s knowledge of colorful jail-cell argot: “So you [as a new prisoner] make a conscious choice to survive and find a benefactor, ‘an old man,’ and become a full-time punk, one step above the yard bitches.” There’s also a trip to Guadalajara that seems pretty unnecessary, involving a fictionalized version of the late Timothy Leary whose main role in the novel is to provide its hero with yet another example of how unfair the world can be. As if he needs more. The gloom does lift whenever Robicheaux’s darkly humorous former partner and best buddy, Clete Purcell, appears. Purcell is a funny and furious man of action who lives to break rules. He thinks the world of Dave, but even he bridles at the latter’s offer of “helpful criticism.” “One day you’re going to figure out you’re no different from me, Dave,” Clete tells him. “Then you’re going to shoot yourself.”

As annoying as Robicheaux has become, one hopes this isn’t a hint of Burke’s future plans for the character. A little R&R; is all that’s really needed. In the meantime, the cynical, non-introspective Clete may make a refreshing substitute.

“Cadillac Jukebox” is available, abridged, on two audiocassettes for $18