I have a 2005 V50 T5 AWD 6spd Manual that has a rather noticeable vibration under moderate to heavy accelleration, primarily between 3,000-5,000 rpm. I was wondering if anyone else has recommendations of what to tackle.

The clutch self destructed shortly after I purchased it, it had been replaced prior but apparently not the throwout bearing... which broke into pieces and flew around the bell housing for a while.

The shop replaced the driver side axle (it had a torn boot) at the same time as the clutch job with a brand new axle from Volvo (I am certain it was new). There was a slight vibration prior to replacement, but it is very harsh now. The passenger side axle is a rebuild from some shop in Denver.

Of the two axles, the new Volvo axle has some noticeable play on the transmission side and the rebuild has no play at all. However, I find it hard to believe that a new axle would be bad. Any ideas or advice for hunting this down? I hate to warantee/replace a brand new axle, but these things are $550 a piece so I don't want to replace the passenger side unless I have to... I'm not sure what else could be to blame, any ideas on what else could be the culprit?

Thanks,
Peter