2001 Sierra 1500 reluctor ring question

My wife has a Sierar 1500 2WD 6cyl that is doing the low speed ABS pulsing. I read this forum and performed the sensor cleaning as described in the TSB from GM. The problem did not go away, so I pulled the ABS fuse for now. When I was cleaning the sensors - which were covered with crap - I noticed a lot of grease between the lobes on the reluctor ring in the hub. I cleaned it as best I could, but I could not get all of it. My question is - should there be any grease visible on that ring at all? If not, then do I need to replace the hubs? If some grease is ok, then I guess I will do a voltage check on each sensor, but I don't want to change the sensors if they are just going to get dirty again. The problem is on both sides. Thanks.

Grease on the ring is normal, but if the grease is rusty in color then the hubs need replaced. Be sure to use Timken bearings, not the cheap ones, or you WILL do the job again.

Thanks for the info. I guess a voltage check for the sensors is next. Will do this week.

The right way is to get an abs scanner on it and look at comparative wheel speed sensor inputs at low speed, also the mounting area of the ft sensors needs to be clean of rust to assure a good ground to the hub, there was a reccall for this in the northern rust belt states.

You are right about the scanner. Guess I will have to borrow one. We missed the recall and now it is no longer active - at least according to the GM website. I may give them a call and see if they will still honor it. Other than that, I made sure that the sensor mounting surface was clean before I re-installed the sensors...guess the scanner route is the way to go. Thank you for the help!