Hey guys i have an AU with 4 speed auto, recently ive noticed that the car is making like a slight shudder as it tries to change from 3rd to 4th. Im not sure what the problem is and and not sure how to check it. I think the transmission does need a service tho. But being a uni student, i run very low on cash so it would help if someone maybe has a tech doc on servicing the transmision.

any help or advice would be appreciated. I just wana fix this before it gets any worse.