Manual tranny problems

ok how do I explain this best well my aspire has less than 90k miles and the diff blew out of the tranny. so I get a tranny from a guy from the net says it has NO troubles whatsoever well tonight I put it in and of course the thing sounds like a Jet takeing off in all gears the faster ya go the louder it gets it whines in every gear somone please tell me that I might have messed something up!!!!!!!!!!!! like a wire hitting something anyone have any troubles with this or what the sound could be I would really be greatfull if not anyone have a tranny for sale *Loud Sobs*