NEW YORK -- For David Lee Roth, morning drive time is turning into a car wreck.

The former Van Halen frontman, barely into his fourth month as replacement for the departed shock jock Howard Stern, is the subject of rumors about his radio demise. Roth's four-hour show was already revamped once, producing an on-air tirade against management. And initial ratings were discouraging.

It appears that following Stern, radio's own rock star for the last two decades, is more difficult for the fast-talking Roth than staying on estranged bandmate Eddie Van Halen's Christmas card list.

"He's a dead man talking," said Michael Harrison, founder of the trade publication Talkers magazine. "Based on reports from behind the scenes and critical reaction, coupled with early ratings, it's not looking good."

The once-spandexed lead singer has rarely hit the right notes since his January debut on New York's WFNY-FM (billed as Free-FM) and six other CBS Radio stations. In a recent broadcast, Roth claimed he was bombarded with four management letters in five days about content and predicted his show could be finished before May.

Several of his on-air sidekicks were dumped as the program struggled to find its groove. Roth disappeared from the airwaves for two days amid the turmoil.

"I think the radio industry expects this will end sooner than later," said Tom Taylor, editor of the trade publication Inside Radio.

CBS Radio spokeswoman Karen Matteo declined to comment on the Roth show. But it was widely believed, even before Roth's choice, that replacing Stern was a near-impossible task -- particularly for an inexperienced broadcaster.

CBS Radio, realizing its dilemma, replaced the self-proclaimed King of All Media with several people, including comedian Adam Carolla (who's also struggling to keep Stern's audience in Los Angeles). Roth landed the plum job in New York, the nation's No. 1 radio market.

Billboards and bus ads heralded the beginning of Roth radio as Howard sailed into the satellite radio sunset with his $500 million deal. It didn't take long for critics to tear into Roth's performance.

"Roth's show is ... skin-crawlingly awful," wrote Rob Sheffield in a Rolling Stone piece. "In these days of bland Clear Channel/Infinity corporate radio, it's bracing to hear a guy who has no idea what he's doing. ... Listening to Roth, you feel actual physical pain."

The nasty cracks soon spread to Roth's competition in the cutthroat New York morning radio market.

"He's a mess, and he's a loudmouth punk," said syndicated radio host Don Imus in a recent critique of Roth.

Over on WKTU-FM, a Van Halen song was played on a Friday morning.

"David Lee Roth singing on that?" asked co-host Goumba Johnny. "More people heard him on 'KTU this morning than on Free-FM."

It wasn't this way back in October, when Roth was rolled out as Stern's replacement. The shock jock hosted the rock star on his radio show, and wished his successor well. But by March, indications from the Arbitron monthly trends indicated Roth was drawing a fraction of Stern's New York audience.

Roth, bristling at what he considered management interference, responded by doing a show that sounded like a hostage tape. He later changed his tune, promising to stick with the program: "I'm going to give it a try. I've invested too much in this show not to."

He returned this week with a renewed enthusiasm, attempting to make the best of the situation.

"You just hope the bitterness and rancor don't continue, and that everybody finds a peaceable ending," said Taylor. "Watching a train wreck -- or listening to one -- isn't a great way to spend your morning."