Steering Wheel - Moan or Vibration When Turning
91oldsmobile04
NUMBER: 91-T-193
CORP.REF.NO.: 133209
DATE: September 1991
SECTION: 3
SUBJECT POWER STEERING SHUDDER INSTALL A "TUNED" OR
HIGH EXPANSION HOSE
MODELS/YEARS 1989-91 CUTLASS CALAIS
This bulletin cancels and supersedes Dealer Technical Bulletins 90-T-44A and 90-T-44B which should be discarded
Models/Years Affected:
1989-91 W/2.5L (VIN U) ENGINE
1990 W/2.3L (VIN D or A) ENGINE
1989-90 W/3300 (VIN N) ENGINE
CONDITION: Customers may comment about a shudder, moan or vibration that occurs when turning the steering wheel under the following conditions:
^ Vehicle stopped with brake applied (or moving very slowly)
^ Vehicle in gear
^ Engine at idle speed
The shudder or moan may occur during parking maneuvers or other situations when the steering wheel is turned while the vehicle is stopped or moving very slowly. It is also sensitive to steering wheel rotational speed as well as engine speed. The shudder is commonly more severe during hot ambient temperatures.
CAUSE: A combination of steering gear valve instability and/or engine firing pulses generating a disturbance that is transmitted through the body structure.
CORRECTION: Install a "tuned" power steering return hose and/or high expansion pressure hose between the steering pump and gear.
1990 Cutlass Calais W/2.3L (VIN D or A) ENGINE
"Tuned" Return Hose
Starting with vehicle number LM717359, 1990 vehicles are equipped with a "tuned" return hose which should reduce or eliminate the shudder condition.
New Pressure Hose
Starting with vehicle number LM744715, 1990 vehicles are also equipped with a new high expansion pressure hose which further reduces the shudder condition.
Vehicles built BEFORE the above listed "TUNED RETURN HOSE" breakpoint, and the shudder condition, may be repaired by installing a "tuned" return hose, P/N 26023904. In a very limited number of cases, the tuned return hose may not completely eliminate the shudder condition. In these cases, the condition may be repaired by installing a new high expansion pressure hose, P/N 26024244 (and removal of the clip from the power steering pump).
Vehicles built ON OR FOLLOWING the above listed "TUNED RETURN HOSE" VIN breakpoint, but before the above listed "NEW PRESSURE HOSE" VIN breakpoint, are equipped with tuned return hoses, but are not equipped with new high expansion pressure hoses.
For vehicles in this range that still exhibit some power steering shudder, the condition may be repaired by installing a new high expansion hose P/N 26024244 (and removal of the clip from the power steering pump).
Vehicles built after the above listed "NEW PRESSURE HOSE" VIN breakpoint are equipped with a "tuned" return hose and a new high expanslon pressure hose and should not exhibit the shudder condition.
1989-90 W/3300 (VIN N) ENGINE
Starting with vehicle number LM778565, vehicles are equipped with a new high expansion pressure hose, which corrects this condition:
In vehicles built before this VIN breakpoint, this condition may be repaired by installing a new high expansion pressure hose, P/N 26026183.
1990-91 W/2.5L (VIN U) ENGINE
Starting with vehicle number MM016754, 1991 vehicles are being built with a new "tuned" return hose which corrects this condition.
In vehicles built before this VIN breakpoint, this condition may be repaired by installing a new "tuned" return hose, P/N 26027298.
Vehicles with tuned return hoses that still exhibit steering shudder, install a high expansion pressure hose, P/N 26027234.
Note: If the above hoses do not repair the shudder condition, please contact Technical Assistance.
Parts are currently available from GMSPO.
ENGINE VIN MODEL YEAR/
CARLINE ENGINE CODE MODEL YEAR HOSE TYPE P/N VIN BREAKPOINT NOTE
N 2.3L LD2/LG0 D or A 1990 TUNED RETURN 26023904 1990 - LM717359 2
N 2.3L LD2/LG0 D or A 1990 HIGH EXPANSION 26024244 1990 - LM744715 1,2
N 3.3L LG7 N 1989-1990 HIGH EXPANSION 26026183 1990 - LM778565 2
N 2.5L L68 U 1989-1991 TUNED RETURN 26027298 1991 - MM016754 2
N 2.5L L68 U 1989-1991 HIGH EXPANSION 26027234 SERVICE ONLY 3
NOTE:
1 USE RETURN HOSE P/N 26023904 BEFORE INSTALLING THIS NEW PRESSURE HOSE. REMOVE P/S PUMP HOSE CLIP.
2 VEHICLES BUILT AFTER THIS BREAKPOINT ALREADY CONTAIN THIS HOSE.
3 USE RETURN HOSE P/N 26027298 BEFORE INSTALLING THIS NEW PRESSURE HOSE.
IF THE HOSES LISTED ABOVE DO NOT WORK, PLEASE CONTACT TECHNICAL ASSISTANCE.