518

If it has all forward gears it's most likely a rear band servo blew a seal or broke. Or the band itself could be worn out. Could even be a broken band strut. Anyway he'll have to pull the pan for an inspection.

Did he drive it much without the throttle pressure linkage on it? If so tell him it's time for a rebuild cause he most likely trashed it. The throttle pressure linkage (kickdown) is absolutely crucial to have working. You can toast a trans. in just a few miles without it.