Easily 100,000 miles or even more provided you do some preventative maintenance.
My 1984 TT, bought it used was built in California and some how managed to find it's way to PA where I bought it..
From what I could tell, had the original drums, brakes and most likely bearings and I bought it around 2003.. Have no idea how many miles on those bearings and they were not pitted or rusted.. Only changed them because I was ditching the expensive star rims and that meant replacing the old drums with newer drums with standard 5 bolt pattern..
I have a 2003 2wd truck which the I changed the front wheel bearings at well over 150,000 miles due to the rotors being worn out and the hubs are integral to the rotors..
One of the biggest issues is lack of care, periodically you do need to disassemble, remove all the old grease, change the seal and refresh with a good grease..
Folks also do not realize that from factory, the bearings often do not have enough grease.. So it is vital to pull, inspect and add a little extra grease when new..
Although keeping in mind, OVER GREASING is just as bad as not enough..
