The Senate Judiciary Committee, not normally in the business of hosting alumni reunions, found itself in the thick of a fractious one yesterday.

Three former committee members, ex-senators Sam J. Ervin Jr. of North Carolina, Joseph D. Tydings of Maryland and Birch Bayh of Indiana, all Democrats, turned out on behalf of private clients interested in a bill that would limit damage awards in price-fixing conspiracies.

The ex-members were not on the same side of the issue, nor were two Carter administration officials--former attorney general Griffin B. Bell and former presidential adviser Stuart E. Eizenstat--who also were part of the all-star cast of interested onlookers.

If yesterdays's hearing was any indication, the custom of senatorial courtesy does not extend beyond a member's active years. The bill, if applied to pending cases, would immunize a handful of companies already found guilty of price fixing from hundreds of millions of dollars in possible damage awards, and their lobbying has been ferocious.

Ervin, who was brought in by the side that favors the retroactive application, did not mince words. After putting his seal of approval on the constitutionality of such an approach, he went on to describe the "legally and morally reprehensible" tactics that plaintiffs' counsel had used under existing antitrust laws to "blackmail" defendants in price-fixing cases.

It happens that a lead plaintiff's counsel in one of the major class action suits that has led to calls for remedial legislation is Ervin's former fellow senator Tydings.

Tydings did not to respond to Ervin's attacks, choosing instead to admonish the committee on the dangers of making the law apply retroactively.

The companies most interested in having the law apply to their cases, Mead Corp., Georgia-Pacific Corp. and Milliken and Co., have been pressing their case in Congress for the last six months.

In addition to Bell, Bayh and Ervin, they have hired former Carter administration attorney general Benjamin Civiletti and former solicitor general Robert H. Bork, who gave up the case when he was recently appointed a federal judge.

"They need all the luminaries to compensate for the fact that they don't have the merits of the case on their side," Eizenstat said during a break in yesterday proceedings.

Eizenstat represents International Paper, a company that settled early and inexpensively in an antitrust suit against manufacturers of cardboard boxes and fears that any retroactive application of a cap could upset its deal.

The testy tone of Eizenstat's remarks was repeated throughout the spirited hearing.

The spectacle was discomfiting to the committee, which has been urging the business community to get its lawyers to work out a compromise.

"I've got five companies from my state on one side of this issue and five on the other," said Sen. Howell Heflin (D-Ala.). "I'm about to the point where I want to knock heads."

But compromise was not in the air yesterday, and as Heflin looked out on a sea of 50 or more lawyers in the hearing room--the supporting cast for the superstars--he observed: "We may be having an unemployment problem nationally , but there certainly isn't any unemployment among Washington lawyers.