Jerky steering in 1999 GMC Suburban

z71 steering is stiff only when turn show right or left 1998

set the front wheels in straight ahead position by driving vechicle a short distance on a flat surface. raise and support the vechicle safely on jack stands.place a drain pan below the steering gear. disconnect negative battery cable.disconnect fluid lines.cap the openings.mark the relationship of the pitman arm to the pitman shaft.remove pitman shaft nut and then remove the pitman arm from the pitman shaft using puller J - 6632. remove the steering gear to frame bolts and remove the gear assembly. TO INSTALL align the flat of the flexible coupling with the flat on the shaft push the coupling onto the shaft until the wormshaft bottoms against the end of the shaft.install the pinch bolt. make sure the bolt passes through the shaft undercut. tighten the pinch bolt to 75 ft lbs. place the steering gear into position guiding the coupling bolts into the proper holes in the shaft flange. install the steering gear to frame bolts and torque to 66 ft lbs.install the coupling flange nuts and washers. make sure the coupling alignment pins are centered in the flange slots. tighten the nuts to 20 ft lbs. maintain a coupling to flang dimension of 0.250 - 0.375 inches. install the pitman arm.install the hoses. you are done except bleeding power steering system. BLEEDING POWER STEERING. fill the the power steering pump reservoir to the proper level and let the fluid remain undisturbed for at least 2 minutes. start the engine and run it for only about 2 seconds.add fluid as necessary. keep doing this procedure until fluid level stop dropping. then raise the front of vechicle so the front wheels are off the ground.set the parking brake and block both rear wheels front and rear. manual transmission should be in neutral. automatic transmission should be in park. start the engine and run it at approximately 1500 rpm. turn the wheels off the ground to the right and left lightly, contacting the stops.add fluid as necessary. lower the vechicle and turn the wheels right and left on the ground.check the level and refill as necessary. if the fluid is extremely foamy, let the vechicle stand for a few minutes.with the engine off and repeat the procedure. if fluid looks foamy. once all done.dont drive vechicle on highway until normal steering is obtain.

Some times just putting pressure on the steering wheel either left or right turnwill allow the key to be turned. What happens is corrosion sets up and does not allow the steering wheel to turn completely to its index position. Just jiggling it back an forth will allow it to index. After you get it to turn properly, squirt a little WD-40 into the key hole and work the steering back and forth while turning the key.

Sounds like the truck is in 4 wheel drive, try turning the front driveshaft, it should turn freely if it is in 2wd otherwise you may have transfercase problem or your front diff is locked in

1. Check if the belt on the power-steering pump is not slipping. Replace belt if so.

2. Check for oil leaks (if yes, there is air in system).

The tirerods on the burbans can get wedged when turning sharp. Have seen a couple do it.

Just to double-check, you can Check for your stearing trim is in the middle and not pushed aside. Once you have done that, take everything apart, gears out and etc... turn on the car. Let the servo center and pop everything in as carefully as you can and close as the middle as you can. Re-assemble and see if it's any better.

Also, check your servo wires leading onto the board. See if any of them are loose or have even fallen off.

Another possibility that I have seen is when you turn the wheel all the way to the lock, the power steering pump is still trying to turn it further, which is why the steering feels jerky. You can blow up the pump, or a hose, by holding the wheel against the lock. You won't turn any wider if you let the wheel come back one quarter turn, but you will take the pressure off of the pump.

When you turn and get the wooble, which way are you turning, right or left.
When you say wooble, does the steering wheel move left and right or is it a sensation you feel in the "seat of your pants".
Let me know.
Regards,

I doubt it's your 4x4. Most transfer case will start turning the front driveshaft, meaning that BOTH front wheels would try to turn.

Could be a brake pad/caliper locking up on your left wheel. That'll make that wheel turn slower resulting in the veering left.

Could also be a wheel bearing. However usually you'll hear a grinding noise to go along with that. And it'll pull rather consistently in that direction rather than suddenly.

Or, what first comes to mind is that your steering box is loose, or the gear inside the steering box is stripped in one spot. Or your front tie rods could be shifting or possibly ball joints. These would cause a sudden shifting/veering.

All of these things are front end related. And also very dangerous. Take it down to any alignment shop, have them put it on a lift, and diagnose immediately.

Worse case scenerio is that a front end part breaks and sends you out of control and into someone else. Please get it checked. A diesel Suburban could do a lot of damage.

Sound like you have a wheel sensor going bad.You will need a scanner to monitor the sensors while driving to see which one is causing the problem

sound like your powersteering pump or steering rack and pinion
could be bad.i would say it is your rack and pinion because if your pump was bad your steering would be real hard to turn instead of being jerky.jerking is usally the sign of a bad rack
samboiv