problem with 1997 Ford Crown Victoria, VIN 2FALP71W8VX18XXXX, with 184,000 miles on it.
The outer rear wheel bearings have no inner races; they ride on a case hardened surface on the axle shafts. This case hardened surface failed on the left axle, and the axle wore about a sixteenth of an inch deep all around. Examination of the right axle revealed no wear, but it did have some cracks in the surface. The axle housing was cleaned of metal particles, and both rear axles, outer rear wheel bearings, and seals were replaced. The ABS exciter rings are integral with the axle shafts, so they are new as well. The rear rotors, calipers, parking brake shoes, and all brake hardware were replaced at the same time, and the brake system flushed out with new fluid. It is possible that some air may have been introduced into the brake system at the master cylinder at that time.
When the car was driven (after having sat for about nine months before this work was done), the ABS brake system operated right at the end of almost every stop. (It felt and sounded like you were driving over a washboard.) The ABS light does not illuminate when this happens or at any other time (except for the short time when the system performs its check at each start-up). There was no problem with the ABS brake system before the axle failure. It had previously activated only on snowy or slick roads when appropriate.
Suspecting that the left rear wheel speed sensor may have been damaged by contact with the exciter ring on the worn axle shaft, it was replaced with a used one from another '97 Crown Vic. The condition definitely improved, but the ABS system still activated inappropriately occasionally (maybe once every twenty or so stops). A new wheel speed sensor was put on the left rear, and the condition is now as bad as it was right after the car was first placed back in service.
Other work done at the same time the axle shafts were replaced:
All four shock absorbers were replaced. (The rear ones were fun!)
All tie rod ends and the idler arm were replaced.Transmission
and torque converted were drained.
Transmission fluid and filter were replaced.
Transmission shifter cable was replaced.Engine
oil and filter were changed.
The check engine light is not illuminated, and no engine codes are stored. I do not have the ability to check for any stored ABS brake codes.