Sammy Rachels, who held the opening-round lead, managed a 1-over 73 Saturday at Egypt Valley Golf Club to fall back into a tie for third. Rachels was joined by Stewart Ginn, Jim Thorpe, Tom Purtzer and Vicente Fernandez at 7-under-par 137.
Bean, who will be in search of his first career victory on the Champions Tour since joining the senior circuit last year, ran off six consecutive pars to start his round before his first birdie of the day at the par-5 seventh. He then birdied the par-3 eighth to make it two in a row and stand at 5 under around the turn.
At the par-3 12th, Bean hit his tee ball close to the hole and watched as the ball stopped within 2 feet of the cup. He tapped in for birdie before hitting a huge drive at the par-5 13th.
Bean played his approach inside three feet for a short eagle putt and left himself with 18 feet left for a birdie at the very next hole. Bean then drained the birdie try to reach 9 under.
The 51-year-old scrambled off the tee at the par-3 16th, but converted a 16-footer to save par. Bean then dropped his approach within 5 feet of the cup for a birdie at the last to secure a share of the 36-hole lead.
'It's about to be fun again,' said Bean, who won 11 times in his PGA Tour career.
Gilder, a seven-time winner on the Champions Tour who is looking for his first win of the season, tallied his first birdie at the par-4 second and added a birdie at the sixth to climb to minus-8.
He hit his second shot within a few inches of the cup for a birdie at the ninth and moved into the lead with a birdie at the very next hole.
Gilder found trouble with a bogey at the 16th, but came right back with a birdie at the par-5 17th.
At the 18th, Gilder hit an 8-iron 6 feet past the hole and sank the birdie putt to assume a share of the lead with one round to play.
'I've hit the ball really well the last two days,' said Gilder, whose best finish this season is a tie for third at the Kinko's Classic.
Hale Irwin, who won his fourth Senior PGA Championship last Monday at Valhalla, shot a 5-under 67 to move within striking distance of the leaders at 6-under-par 138 along with Mark McNulty, Jerry Pate, Fred Gibson, James Mason and last year's runner-up, Eamonn Darcy.