Finally i fixed my dryer problems(squealing noise and longer dryer time).
For squealing noise, I cleaned the ball hitch thoroughly and applied some grease.
For longer drying time,I had to clean almost every single item.Lint was all over inside the dryer.
Vent was fine but the door and element surrounding areas had about 2" lint build up.
It's work like a new machine.
Thanks a lot "AJ" again for your help.(service manual and advice).