"Uncle Joe Shannon" is a derelict tearjerker that arrived unscreened and unheralded at a few area theaters on Friday and will depart unmourned tomorrow. The quicker it achieves oblivion, the better for everyone concerned, especially Burt Young.

Young is the likably Runyonesque character actor familiar to contemporary movie audiences as Jack Nicholson's first client in "Chinatown," a gangster's collection agent in "The Gambler," James Caan's sidekick in Sam Peckinpah's "The Killer Elite" and Talia Shire's grungy brother in "Rocky."

It appears that the success of "Rocky" encouraged the utterly misbegotten production of "Uncle Joe Shannon." Perhaps the producers, Robert Chartoff and Irwin Winkler, imagined that they couldn't miss with the formula of a diamond-in-the-rough actor writing a starring role for himself as a bum who comes back. If the movie industry required proof that this formula wasn't foolproof, they've got it now.

Outsiders will be merely depressed and dismayed at the sight of Young wallowing through this mawkish superdowner, in which be portrays a once great jazz trumpeter who plunges into alcoholic squalor after the accidental deaths of his wife and little boy and then pulls himself together by taking responsibility for a crippled waif. Insiders might have spared Young the indignity of his masochistic folly by discouraging the project at the outset.

Like Rod Steiger in "On the Waterfront," Young's patrons should have looked out for him a little. They must have known that the scenario originated in a tragic event from Young's own life. Joe Shannon returns from a triumphantly productive day, cutting a new album and then dazzling the audience at a symphonic concert while performing in dazzling white evening clothes, to discover that his beloved wife nd child have perished in a fire. Several years ago Young returned home to find that his wife had apparently killed herself and their little boy.

Of course, one can imagine a particularly painful autobiographical episode being transumuted into an effective screenply. The odds against it happening in real-life moviemaking just happen to be astronomic. The maudlin, turgid consistency of the finished film must have been apparent in Young's screenplay.

The relationship of Young's Joe, stumbling around an East Los Angeles slum with his trumpet clutched in his hairy paw, and Doug McKeon's Robby, a defiant orphan suffering from a gimpy, cancerous leg, was obviously intended to provoke more tears of pathos than Chaplin and Coogan in "The Kid" and Beery and Cooper in "The Champ" ever inspired.

Young is a relatively new presence on screen, and his personality, while enjoyably gruff and motley, is scarcely primed for transcendant pathos. He can't redeem episodes as compulsively grotesque and excruciating as Joe being hooted off the bandstand at a jazz club and Joe and Robby trying to raise money as sidewalk entertainers while dressed in stolen Santa and Santa's helper costumes.

"Uncle Joe Shannon" aspires to be an exalted, purgative heart warmer. It's merly so indiscriminately pathetic and mercilessly dismal that you feel like crying "uncle."