04 Avalanche steering wheel turning on it's own

[gregorb23]

I have a 04 Avalance and had a problem where the steering was hard to turn one direction. I changed the pump and it did not fix the problem. I then changed the gear box. Now when sitting still the wheel turns on its own. When moving and you turn the wheel keeps turning in that direction. I have searched all over the net and have not found anyone with this problem. Can anyone help.

[Doug_Scott]

Not having ever had your type of steering chuck apart, I would look for some kind of valve being not centered inside the box itself. Hard to get the steering shaft off due to indexed input shaft on box, and same for pitman arm. Pitman arm can only go one of 4 positions, virtually impossible to get that wrong and be able turn both left and right.

Is this a completely different box? Odd to have two boxes have similar issues, when having just one do it is odd enough.

[aflesch]

You need to reinstall the gearbox. The "home" position of the steering wheel is probably off (most likely by 1 revolution). When the toe was set it compensated for it so all seems normal. In order for the power assist valving to work correctly it needs to have the correct "home" position. Basically when you are going straight it thinks you want to turn. You also could have a defective gearbox.

[aflesch]

It almost sounds like the torsion bar in the gearbox is broken so the rotary valve doesn't close when you stop turning the wheel.