Volvo: Transmision

Question
I have a 1993 volvo850glt automatic that I just put a used transmission in. It will go in reverse as soon as I put into gear as for going forward I have to bring the rpm upto around 4500..... What could be my problem? Have reset computer have checked fluid and flushed system.

Answer
If whay you are saying is you have to rev the vehicle in gear to 4500 rpm to get it to move ,then it looks like the used trans is no good .If you have checked the fluid level running in park and it has sufficent and there are no connection problems .no flashing gearshift lights then it looks like another trans is needed .