I am on my 3rd brother and oil was not mentioned in the manuals. I wouldn't oil anything until I called the customer service number in the manual to ask them. I think they are going to tell you it needs no oil.
Now, when you have it serviced it is possible the serviceperson will oil it.
Use our search field and searh 'oil'. There are lots of post on this topic that might give you additional information too. This is a good one.
http://www.quiltingboard.com/t-45573-1.htm
Good luck.
Regards, Dorothy