I have a 1999 Volvo sx out drive with a seized upper. I replaced it with a used one that i bought. I am having trouble with it going into forward gear. I am thinking the cone clutch is slipping. sometime it engages sometimes it needs a higher rpm and bangs into gear. Reverse works fine all the time. I tried adjusting the linkage back and forth a few turns but there was little change. is there anything else that could cause this problem. could I just swap out the old clutch for the one in my siezed drive or will i need to do any shimming?