Ok I hope somebody can tell me wether this is normal or if it is a problem. The transmission in my 1990 SC is really rough, at high accelartion it shifts pretty smoothly but at low acceleration is seems kinda hard, not knocking though and also when the car shifts into overdrive (4th gear) it sounds like it knocks. Can somebody please tell me what i should look for or what i should check, the fluid level is good and There is no leak.

I would probably start small, check the tranny mounts if they don't seem like they're shot try a trans conditioner, like trans-x or sea foam for transmissions.If you don't already have one maybe think about investing in a transmission cooler. If you mount it in front of the radiator be sure to mount it at least three inches away otherwise the rest of your cooling system will go down hill.