A couple weeks ago i was doing a full service of brakes and anything with a nipple greasing it ,mainly due to some deep water and mud adventures
well i got to my front hubs removed the abs sensor and this rusty coloured grit was in there ,so thinking this can not be good and knowing the price of new ones there was no way i was gonna give up yet so off came both hubs out came the wd40 and sprayed away emptied it out and continued until it was a clear liquid coming out i also turned the hub so the gears moved within once this was shiney and clean i started sprayng INOX extreme pressure grease into the hubs turning the gears so the grease reached all areas this was i lenghty process when i was statisfied in the amount of grease in there they went back on and serviced almost like new hubs
who said you can't service them it just is a couple hour job
I did not post this up after i did it as i wanted to drive with it for a couple of weeks and i have done about 1500k in that time just to see if it worked correctly well last night i removed the wheel and brake roto to have a look in the hub through the abs sensor hole and grease is still same colour and spins with ease ,so in my service i reckon i have exteneded the life of the hubs by a fair bit ,and saved me over a thousand bucks

cheers Kelvin