Vehicles have a large variety of systems. You should specify make, year and model, if you expect any constructive help.How to tell if my axle is bent ?
Make your wheels and steering wheel straight and go into a straight line. If your axle is perfectly straight, theoretically you would go straight. If your axle is bent, it will slightly swerve left or right. Replacing an axle is very difficult to do yourself, and getting it done at a mechanic would run you about $1000 per axle.