Despite the well-publicized strain between the president and the top House Democratic leader. insiders predict relatively smooth sailing for the Carter civil service "reform" bill when the House takes it up this month.

There had been speculation that Speaker Thomas P. O'Neil (D-Mass.) might seek revenge blocking the bill because of the firing of his old friend from the number two job at the General Services Administration.

But congressional and White House sources say Vice President Mondale has been talking with O'Neil about the civil service reform package, and that O'Neil will stick by his pledge to guide it through the House.

Both Senate and House committees handling civil service matters have approved "reform" bills. But their versions are very different from what the president wants. The House bill, in particular is viewed by top administrative aides as "objectionable" because of various riders attached to it.

Those House committee riders coupled with the feud between O'Neill and Carter present the speaker with a golden opportunity for revenge if he wants to take it now. O'Neill is furious over the "dumping" of 35-year career man Robert Griffin a personal friend, from the GSA. O'Neill feels he was betrayed by the White House, which he said promised him Griffin would be allowed to stay despite personality conflicts with Jay Solomon the Tennessee businessman who heads the scandal-rocked agency.

Backers of legislation to expand the political horizons of federal and postal workers (and their unions had hoped that the Carter-O'Neill rift might play into their hands. The House civil service "reform" bill contains language that would remove political restraints from government employes allowing them to collect funds for partisan candidates manage campaigns or run themselves as candidates in partisan elections. Those actions are now by the Hatch Act.

The House has previously approved liberalization of the Hatch Act. But it has been dead in the water in the Senate. To force the Senate to vote on it, the House Post Office-Civil Service Committee has linked Hatch Act "reform" to Civil Service "reform" in the same bill.

White House sources say the president is firmly committed to the Hatch Act changes. But he doesn't want them part of the civil service "reform" bill. "It (the Hatch Act) is on its own track and should be considered separately from civil service reform," a top Civil Service Commission official said.

Privately, White House aides fear that the Hatch Act rider could hurt chances of the Senate approving civil service "reform." Governmental Affairs Chairman Abraham Ribicoff (D-Conn) is opposed to the Hatch Act changes, and union lobbyists have been unable to find a senator with the influence to be floor manager of the bill. For that reason, the unions are pleased that the civil service "reform"-which carries little other benefit for rank-and-file members-is tied in the House to the Hatch Act changes.

A source close to O'Neill said that Mondale has been talking with the speaker about civil service "reform" and about the "problem" of its linkage to the Hatch Act.

People who know the speaker say this is not to say that he will kiss and make up with the White House over the Griffin firing. They are waiting to see what kind of job the White House comes up with for Griffith. But they do not expect O'Neill and Carter to butt heads over the civil service package.

And the plan still is, sources say, to remove the Hatch Act changes from the House bill either on the floor or by prearranged agreement, when Senate and House conferees meet on the measure.