What timing.....I was just coming to post about this very problem. I was quoted $1,900 (roughly 10% of purchase price on our used '10 LT Traverse) to replace the steering gear, pump, and lines (plus alignment and shop fees) at the dealership. I see RockAuto has two racks (both ACDelco) PN#20964166 and PN#22902260. Can someone confirm the right number?
I'm Not 100% why they want to replace essentially the entire system, but that is what they quoted. A quick check on RockAuto puts the gear at $342 (1 left at $253), and the pump at $125. Hoses are another $50-$60 bucks. All ACDelco parts. That's $527 in parts. Lets assume a $75 alignment as well. That's $602 in hard costs. So $1,300 in labor to replace those parts. Is there something I'm missing from the system that makes it worth $1,300 for them to change it out instead of me.
Here are the symptoms that prompted the diagnosis:
At low speed when transitioning from off throttle to on throttle, assist is completely lost. Almost as if it is getting pressure to BOTH sides. The wheel becomes virtually impossible to turn. So for instance, when pulling out of a driveway onto a busy road, as you sit there idling waiting for your chance to pull out the steering works great. Then as you press the gas pedal and turn the wheel the wheel "locks" in position, and take a small act of god to complete the turn (I have to use both hands and make a serious effort to complete the turn, Shelly has to drive in the other lane until the assist comes back). Once moving the assist comes right back with no problems. When idling the assist is perfect, when under light throttle and making a turn it's perfect. For instance, driving through a parking lot, up and down the isles, no problem, pull into a parking spot no problem, plenty of assist, as soon as you transition from off throttle to on throttle, it locks. The case is exceptionally bad when reversing uphill, as you are on/off the throttle as you move the vehicle into the desired position, the assist locks and unlocks the wheel multiple times.
SO.....Anyone have any experience with this steering issues? It sure seems to me like the lines and pump have to be working at least at some level to keep assist at idle, and at speed. Should I replace the rack first, then the pump, then the lines? Other way around? Lines first, then pump, then rack? I've read on other forums of just the rack getting replaced, and that solving the problem.
I'll be sure to have someone on hand with a camera when I do the repairs to get a write-up for it done, as I can't seem to find one anywhere else.