hi guys need some help please
i have a 2001 ls 4x4 and i just replaced the power steering box with one from the wreckers and since then my power steering pump is wining. so is the gear box no good or is the power steering pump going now any in put would be great thank

 

Whining noises are usually air in the system.

Check for leaks first.

Top up the fluid. Start the engine, and turn the thing from right side lock to left side lock and back a half dozen times. Stop and check the fluid and top up if needed. Check for leaks again. Fix any leaks as you find them.

Repeat that process a few times as needed until the whine goes away. It could take a few times.

If 4 or 5 repetitions of that doesn't fix it, look for leaks again, especially in the return line (sucking air into the system).