07 Tundra abs issue

So my 07 Toyota tundra, 5.7 V8, 102k miles, has
been flashing the 4hi 4lo lights. The skid and abs
lights are solid. (note: check engine is not on)

What happens is the computer resets every time I
start the truck so no lights appear. After braking
the first time the abs grinds.

I took it to a shop to have them scan it with the abs
code reader and 3 codes appeared. Left and right
rear abs sensors were shot, and low voltage. I
replaced the sensors and found gear grease with
metal shavings on the driver side sensor.

Two weeks went by with no grinding or lights and
all of the sudden they are back. Anyone else
experience this issue?