now what??????????????

Discussion in 'The Garage' started by wasted wages, Dec 31, 2003.

  1. wasted wages

    wasted wages 3/4 ton status

    Dec 3, 2003
    Likes Received:
    Dallas Texas
    My 97 Yukon (sorry I know it's new sheet metal)has a steering problem that I can't seem to figure out,,,
    #1 It's bone stock
    #2I've changed the pitman arm,idler arm checked the tie rod ends ,ball joints,,all are tight
    #3 the truck has less than 70K
    #4 The problem is loose steering "feel" when driving straight and as soon I turn the wheel for a correction the truck jerks as if the steering is catching up to the steering input,,,,there is no mechanical slack,only the feel of loose steering.the problem also comes and goes
    and is not constant.
    #5 I found out today that a steering sensor fails quite often on 97/98 Chevy/GMC, the sensor is located on the steering column.
    #6 I looked under the dash tonight and there is in fact a sensor ring on the column.
    #7 the strange thing is what does this sensor control?
    There are only 2 hoses from the P/S pump directly to the steering box. There is no wires/valves on the pump or steering box that the sensor would appear to control,so if the computer is taking input from the sensor how does it control the pressure on the fluid side of the system?

    any service techs got the answer to this one,,,what am I missing????
  2. bryguy00b

    bryguy00b 3/4 ton status

    Apr 7, 2002
    Likes Received:
    Rochester, N.Y
    well..i find it nuts that a rig would have a sensor to help control steering to begin with!! /forums/images/graemlins/eek.gif
  3. playtoy1

    playtoy1 Registered Member

    Nov 25, 2003
    Likes Received:
    central michigan
    hey my 98 has the same problem and ive heard the same thing that that sensor is my problem hope some one can clear this up for the both of us
  4. xflatrater

    xflatrater Registered Member

    Nov 28, 2003
    Likes Received:
    Shamong NJ
    This snippet from Delphi should clear it up a bit …basically if the steering [handwheel] sensor fails the system may default to high assist at all times …if the sensor fails intermittently the system may become very erratic..There is a service bulletin that also addresses the problem with a new sensor that has been updated.

    Variable-effort systems are enhancements to standard power
    steering systems. They automatically adjust the required steering
    effort in relation to engine RPM or vehicle speed. Delphi’s variable effort
    steering systems incorporate a controller that varies electrical
    current to the actuator device with changes in vehicle speed.
    Other input parameters may be added to the controller to provide
    even greater sophistication in the steering system.

    Typical Application
    The Electronic Variable Orifice (EVO) system changes steering
    effort by regulating fluid flow from the power steering pump.
    A variable discharge orifice actuator mounted at the pump
    discharge fitting serves as the regulating device. The EVO
    system is available for rack and pinion and integral systems.

    Performance Advantages
    During parking maneuvers, the actuator provides high pump
    flow for easier steering effort. At highway speeds, the actuator
    reduces flow in proportion to vehicle speed for improved highway
    feel and stability. Delphi’s EVO system can be tuned to precise
    system performance specifications.
  5. Confedneck

    Confedneck 3/4 ton status

    Nov 1, 2002
    Likes Received:
    Lehigh Acres, Florida
    i say replace the sensor for the VAPS.. as stated above.. variable assist power steering.. the faster you go, the less assist you should get, and more assist for slower (see parking lot manuvers) driving..

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