Once again, the vacuum gods have smiled upon me and brought into my possession a vacuum I've been looking for quite awhile now. A Eureka Ultra model 7440A, complete with attachments and papers circa 1985! I must say with the converter it has fairly decent suction. Unfortunately after about 5-10 minutes, I noticed the motor slowing down and after I turned it off a faint burning smell. I took the cover off and the armature looks okay. I'd like to take it apart and see if I can grease the bearings. Is it difficult to do this? Any technical info would be appreciated. Thanks.