CAPE CANAVERAL, Fla. --- Inspectors have found more cracked bearings in the massive crawlers that carry shuttles to the launch pads, and there could be further discoveries before NASA and contractor United Space Alliance figure out what repairs are needed.

Only a planned refurbishment led to the discovery, when workers removed two of 16 steel-alloy hydraulic cylinders on one of the 5.5-million-pound crawlers. There are two bearings per cylinder, one at each end.

"The crawlers were running fine," NASA spokesman George Diller said at Kennedy Space Center.

But workers have now discovered that 19 of the 9.5-inch-wide, doughnut-shaped, 40-pound bearings are damaged on Crawler Transporter No. 1. On the second crawler, 15 were found damaged so far.

Further inspections with ultrasound and X-rays could reveal more damage, Diller said.

If all goes well, there would be enough bearings between the two crawlers and the nine spares -- one more spare than was reported Monday -- to get one crawler running in time for the scheduled Sept. 28 launch of Atlantis. The manufacturer could make more if necessary, but it's not clear how long the process would take.