Depends on the direction of the bend.
If it's bent side to side, most likely it will dog leg and not track straight without the proper equipment to straighten it before/after it's welded back together.
If it's bent upwards in the middle (shortening the wheel base), it could cramp the drive shaft and cause excessive wear or binding
If it's bent down in the middle (lengthening the wheel base) it could stretch the axle, or even allow it to slip from the trasnfer case/transmission or from the rear differential.
All these examples are pretty extreme, but you get the idea. I'd take it to have it checked out on a frame straightener before purchasing it.
If it's bent side to side, most likely it will dog leg and not track straight without the proper equipment to straighten it before/after it's welded back together.
If it's bent upwards in the middle (shortening the wheel base), it could cramp the drive shaft and cause excessive wear or binding
If it's bent down in the middle (lengthening the wheel base) it could stretch the axle, or even allow it to slip from the trasnfer case/transmission or from the rear differential.
All these examples are pretty extreme, but you get the idea. I'd take it to have it checked out on a frame straightener before purchasing it.