Steering box

David97 · July 5, 2015

Anyone know if a steering box out of a 1990 gm pickup work in my 97?

1997SierraSLT · July 6, 2015

I don't beleive they are interchangeable. The 97' uses a completely different power steering pump w/ solenoid for the variable speed steering feature.

David97 · July 6, 2015

So you don't think the gear boxes will interchange or the pump? I believe all I need is the gearbox.

1997SierraSLT · July 7, 2015

I know for sure the pump is not interchangeable. In a conventional steering gear box (pre 97'), there is a torsion bar coupled to a control valve. The amount of force applied to the steering wheel determines amount of hydraulic pressure developed at the steering gear box.

In the 97' vehicle, the power steering pump incorporates a solenoid valve controlled by the ECM to vary hydraulic pressure going to the steering gear box in lieu of a torsion bar arrangement.

I would speculate though that it would be feasible to put a 90' steering gear box into the 97' but you'd have to put a pre 97' pump on it as well.

You'd definitely want to do quite a bit of research to determine fit/compatibility.

Just as an FYI, the 96' model to my knowledge did not incorporate the VSS (variable speed steering) feature. The 96' used a conventional power steering pump/steering gear box design. The reason I bring this up is because 96' was the first year of the Vortec engine which may impact type of power steering bracket used.

Interesting reading below:

http://www.pacificp.com/forum/viewtopic.php?t=10246