1992 GMC sierra two wheel drive 4.3l V6 Have a vibration or rubbing noise when I turn the steering wheel sharply to the left at parking lot speeds.

Struts would not cause vibration problems, A CV joint could, turn your vehicle in a parking lot hard right, make a circle than turn left make a circle ,if you hear a noises you have a cv joint problem. If you feel vibration on the steering wheel its in the front, if you feel it in the seat its in the rear.
Tires out of round & Balance very common as well brake rotors cause vibrations.

I'm thinking your power steering rack needs servicing! may be air in the hydraulic lines. did it start right after you replaced the pump? did you run the fluid resivour dry by any chance?

check the steering arm damper shocky as it may be failing and not providing the proper dampening effect to the steering. Check the wheel bearing adjustment and condition.

Have the wheel bearings checked.

Hello! This is a known problem that is addressed by the following Technical Service Bulletin...Guru...saailer

Subject:Steering System Moan, Groan, Shudder and/or Vibration Type Noise During Low Speed Turning Maneuvers (Replace Steering Gear) #04-02-32-007A - (12/01/2004) Models:2004-2005 Buick Rainier
2003-2005 Chevrolet TrailBlazer, TrailBlazer EXT
2003-2005 GMC Envoy, Envoy XL
2004-2005 GMC Envoy XUV
2003-2004 Oldsmobile Bravada
Short Wheelbase Utilities Built Prior to VIN Breakpoint 52123375
Long Wheelbase Utilities Built Prior to VIN Breakpoint 56137280
This bulletin is being revised to remove the 2002 model year and add the long wheelbase utilities. Please discard Corporate Bulletin Number 04-02-32-007 (Section 02 -- Steering).

ConditionSome customers may comment on a moan, groan, shudder and/or vibration noise while making low speed turning maneuvers. Customers usually notice this condition in parking lot turning maneuvers.
Correction

1. Diagnose the power steering concern. Refer to Symptoms - Power Steering System (SI Document ID #670351).
2. Replace the steering gear with a newly designed steering gear. See the parts information below. Refer to Power Steering Gear Replacement (SI Document ID #742314).

Parts Information

Part Number

Description

Qty
88965356
Gear Kit, Steering
(Short Wheelbase Utilities)
1
88967181
Gear Kit, Steering
(Long Wheelbase Utilities)
1
Warranty InformationFor vehicles repaired under warranty, use:

Labor Operation

Description

Labor Time
E9740
Gear Assembly, Power Steering - Replace
Use published labor operation time
E2000
Toe, Front - Adjust

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like driving parking lot speed, the steering wheel or the back shakes??? = bad tire.

there is a problem with the steering shaft going to gear box 2 out of 10 trucks have this problem gmc and chevy ive done a few, its a dealer part, replace that first then see if the other rubbing noise is there, but the knock noise is the shaft, i had 2 with about that mileage they were out of warranty, good luck start there first.

Jack up the front end and put stands under it and block rear wheels. Look at axle boots and see if they are cracked. Try turning wheel back and forth sharply and see if you can hear any clicking. Problem could be outer axle joints. If the boots are cracked or you hear a clicking noise you will have to replace the axle. The axle and boot come as a complete unit. Please let me know what you find out.

1st let me make sure I understand your Jeeps 4 wheel drive. I believe the quadra trac system is a full time 4 wheel drive, there is no 2 wheel drive setting, only a separate 4 Lo (for very slow speed). If this is correct, the problem is, the quadra trac system you have is supposed to compensate for any variations in wheel speed, whether it's driving in the snow, or cutting the wheels sharply to park on dry pavement. What u describe is typical behavior of a part time 4 wheel drive system. The problem is, your full time 4x4 should be compensating for this, and it's not. So, let me know if the above info about your 4wd is accurate (no part time 4wd setting, no 2wd setting, only full time 4wd and 4Lo setting. If it is, the system is not compensating for changes in the wheel slippage correctly.

Wheel bearings.
For quickly ruling out the CV Joint, in a parking lot, turn one way in a sharp circle, then the other way circle sharply. A clicking sound is indicative of a bad c/v joint or 1/2 shaft.
Humming while in motion (most of times it will only occur during a specific speed range - over a certain speed goes away) says a wheel bearing is shot.
Normally you should replace both at the same time... however you can check with a laser temp gauge each front hub after driving. The hotter one is bad - or a less scientific approach is to swerve going down the road. and listen for an decrease in noise going in one diretcion over the other.
If you are turning the steering wheel right, and the noise goes away, the right bearing is bad and vice versa.

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