guibo inquiry

'93 325i automatic... started hearing a groan (like wheel bearing problem) at low speed, gets louder and higher pitch (tho not whiny) at higher speed. Suspect wheel bearing decay or hopefully an aging guibo. Has anyone experienced this symptom and was it your guibo?
I can change a guibo, will be doing that this Sunday, but was just curious as the wheel bearing change out will be close to $500 in parts and that crazy tool needed to do the job. Hoping not to have too much into this in one paycheck.

How much it cost to you in changing the Guibo?

About $54 for the guibo and $8 or less for the 6 new nuts (recommended) and sweat equity. Need to remove the exhaust pipe from the header/pipe flange and the heat shield to give adequate room to remove or lower the drive shaft exposing the guibo. Not complicated but somewhat time consuming. had it done in about two or three hours with #2 son helping.