Toyota Repair: previa van, rear drive shaft, drive shaft

Question
Would the drive shaft cause a shimmy (spelling?) in this type of van?  A friend of mine had been told it was the "front drive shaft" causing the shimmy.  They paid to have it fixed.  It still shimmies and now they are being told it is the rear drive shaft.  I will admit to knowing little about cars, but something just sounds odd about this.  I just wanted to know if it is possible.

Answer
Is it 4WD?
A front SAD (secondary accessory Drive)shaft may cause noise and no shimmy, but a front drive shaft in a 4WD will cause a shimmy.
If you paid for a repair that didnt fix anything , get a refund.

A bad rear u joint will cause a shimmy.

Mike