I spent a day to investigate why I had that high friction in my focuser. I found two things that cause that.
First:
The friction in the fine adjuster gearbox was very high, caused of aging grease.
Second:
One of the screws that press the bearings against the stell plate was to short.
Here you can follow the details if you find it interesting:
http://www.astrofriend.eu/astronomy/...-friction.html
I think that the problem with aging grease can be a common problem, my EQ6 mount is very stiff too. Maybe time to take it apart and regrease it.
/Lars