having an intermittent abs tracs issue. i cleaned the abs sensors up front, the were covered with grit and grime. is it ok the clean the hole the sensor fits in without damaging something and what should it be cleaned with. after cleaning the sensor the vibration is almost gone. on this 87 850 i cant find the reluctance rings, i'd like to clean them too.

 

Clean away my friend. No harm will come to the parts.

 

You can use brake cleaner to safely clean the holes and to wipe down the sensors too.
The reluctor ring should be on the axle right at the end where it fits into the hub assembly. Brake cleaner and compressed air work great to clean.