The voice of Rep. John D. Dingell (D-Mich.) was uncharacteristically low, even silky, as he inquired of General Dynamics Board Chairman David Lewis if he knew "a Mr. Fursten."

"It was John doing his Edward Bennett Williams number," says Rep. Gerry E. Sikorski (D-Minn.), a junior member of the House Energy and Commerce subcommittee on oversight, which Dingell chairs.

When Lewis pleaded ignorance, Dingell pounced. "Mr. Fursten" turned out to be a dog whose $155 kennel bill at Silver Maple Farm in St. Louis had been paid by the taxpayers.

Since that February day, things have not been quite the same. Somehow, Fursten the Dog said it all about encouraging defense contractors to reach for the stars in billing expenses and auditing bills years after they have been paid. Now there is talk that when the House votes on the 1986 budget, defense spending will be frozen, except for an inflation adjustment.

The Pentagon has so much money stashed away "against inflation" -- as revealed when Defense Secretary Caspar W. Weinberger confessed the other day that he had come up with $4 billion he didn't know he had -- that no immediate effects will be felt.

Nonetheless, Dingell is getting credit for reversing the natural order of things: the president annually requesting billions more for defense and Congress meekly going along.

House Budget Committee Chairman William H. Gray III thinks that the House will find the courage to vote down an increase in the Pentagon budget because of what Dingell unearthed.

"The Dingell hearings were the shot in the back of the head," he says. "The people are furious. Reagan promised to end waste, fraud and abuse in government, and now they see that he only means it for welfare and nutrition programs, but not for General Dynamics."

After years of hearings, conducted mostly by Sen. William Proxmire (D-Wis.), about defense contracts that would make a Mafioso blush and about products that don't fly, shoot or float, the country is up in arms.

Dingell modestly says that without the spare-parts horror stories brought out by his colleagues -- the $600 toilet seat cover, the $436 hammer, the $7,600 coffee maker -- "it would be business as usual."

A former Wayne County prosecutor, Dingell is huge with a booming voice. He has been in the House for 30 years, ever since he succeeded his father, a much smaller and less truculent man, who taught him important skills, like being nice to Republicans and giving backbenchers a break.

Dingell is a hunter. On his office walls hang trophies of the chase. He has the same zest for stalking freebooters. He is now the most formidable investigator on Capitol Hill, and his foot-to-the-floor approach and thunderous demeanor with haughty witnesses have earned him the nickname "The Truck."

"Up here we say, 'Don't mess with The Truck,' " says a colleague who watched Dingell wrest documents he required when Rita Lavelle and Anne Burford were his quarry.

Weinberger, who is still to testify before Dingell, and the corporations still have not gotten the word about Dingell. Although the Defense Department inspector general recommended the disbarment of the three top executives of General Dynamics, which does 94 percent of its business with the Pentagon, they are still in place.

With the help of his ace chief investigator, Peter Stockton, Dingell has been on the trail of General Dynamics for a year. He hired as part-time volunteers three serious Pentagon auditors -- Leslie Parfitt, Thomas Ansley and A. Ernest Fitzgerald -- to assist in what he delicately called "an SEC matter."

"Our bosses were delighted to get us out of the building," says Fitzgerald, whom Richard Nixon fired for airing a $3 billion cost overrun on the C5A.

It was in a sense a Security and Exchange Commission matter, since General Dynamics had made more or less full disclosure in its reports to the SEC. Turning the Pentagon auditors loose on these papers was like unleashing bloodhounds in a meat locker: They sniffed out charges for club memberships, junkets to Paris, mattresses for aching executive backs and, most egregiously, a $15,000 contribution to the Grace panel on waste and fraud in government.

Dingell will hold more hearings on General Dynamics. The Democrats are delighted. At last they see a way of being hard on the Pentagon without being soft on defense and of maybe doing something about the deficit, which the public has at last decided it doesn't like.