Left turn hard at low speeds

EI06002 - 670 GEAR BOX POWER STEERING PUMP, P/S PERFORMANCE
CONCERNS
TECHNICAL SERVICE BULLETIN
Reference Number(s): 05-02-32-008C, Date of Issue: March 28, 2011
Superceded Bulletin(s): 05-02-32-008B, Date of Issue: July 18, 2007
Related Ref Number(s): 05-02-32-008, 05-02-32-008A, 05-02-32-008B, 05-02-32-008C
ARTICLE BEGINNING
CONDITION
In rare cases, customers may comment on a lack of steering assist when stopped or during parking lot
type maneuvers. A lack of steering assist could occur if the brakes are applied and turning the
steering wheel with the vehicle stopped or during parking lot type maneuvers. This condition will go
away or greatly improve once vehicle begins to move or is above parking lot speeds. Attempting to
steer a stationary vehicle, with the brakes applied, preventing forward motion will require additional
steering effort. This concern can be aggravated by worn tires, low tire air pressure, low power
steering pump pressures, and tires larger than stock size.
CORRECTION
1. Perform the "Power Steering System Test" found in SI. Make any necessary repairs based on
system diagnosis.
1. FOR 2500 AND 3500 VEHICLES ONLY - If diagnostics did not lead to any repair, this
concern is a normal operating characteristic. No further repairs should be made.
2. FOR 1500 SERIES VEHICLES ONLY - If diagnostics did not lead to any repair, this
concern is a normal operating characteristic.
2. If a 1500 Series vehicle is equipped with a 670 gear box, replacing it with a 680 gear box may
increase the customer satisfaction.
3. To determine if the vehicle is equipped with a 670 gear box, inspect the mounting bolts that
attach the stub shaft housing. A 670 gear box will only have 3 mounting bolts. If the stub shaft
housing does not have any mounting bolts or has 4 bolts - DO NOT PROCEED WITH THIS
Affected
Model(s):
2003-2006 Cadillac Escalade, Escalade ESV, Escalade EXT; 2003-2006 Chevrolet
Avalanche, Suburban, Tahoe; 2003-2007 Chevrolet Silverado Classic; 2007-2010
Chevrolet Silverado 2500-3500 Series Only; 2007-2012 Chevrolet Suburban 2500-
3500 Series Only; 2003-2006 GMC Yukon, Yukon Denali, Yukon XL; 2003-2007
GMC Sierra Classic; 2007-2010 GMC Sierra, Yukon XL 2500-3500 Series Only;
2007-2012 GMC Yukon XL 2500-3500 Series Only
Supercedes:
This bulletin is being revised to add model years and models. Please discard Corporate
Bulletin Number 05-02-32-008B (Section 02 - Steering).
IMPORTANT: In all cases, it is recommended that the proper tire size and the
maximum tire pressure is set according to the manufacturer's
specification as noted on the door placard; especially for the front
tires.
EI06002 - 670 GEAR BOX POWER STEERING PUMP, P/S PERFORMANCE CONCE. Page 1 of 2
2/24/2012
BULLETIN. The vehicle is not equipped with a 670 gear box.
4. If replacing a 670 gear box with a 680 gear box, it will be necessary to replace the power
steering gear, union fitting and both inlet O-ring seals.
PARTS INFORMATION
Parts Information
WARRANTY INFORMATION
For vehicles repaired under warranty, choose the one labor operation that reflects the corrective
action:
Warranty Information

Part Number Description
88965542 Power Steering Gear
26025709 Union Fitting
26001594 Inlet O-ring Seal
Labor Operation Description Labor Time
E9050 Pump Assembly, Power Steering - Replace
Use Published Labor
Operation Time
E9740 Gear Assembly, Power Steering - Replace
Use Published Labor
Operation Time
EI06002 - 670 GEAR BOX POWER STEERING PUMP, P/S PERFORMANCE CONCE. Page 2 of 2
This is a tech service bulliten, but also check to see if the shaft on the pump broke, try pulling it outward if it moves to much, it probably the pump.

Dirt may be an issue as far as the pressure relief valve clogging up. If you can try purging the old fluid it might help. How are the brakes? Hard pedal or normal? Try this, pump the brakes with the truck off, pump until all assist is gone. Hold pedal down and start the truck, pedal should sink a bit then rebound a bit. It is more important for it to sink(soften). As far as the 670 vs 680, if it turns out to be the box, now is the time to replace with the updated one, I assume you are keeping it?

Yes there bolts that go through the frame. Use the part number in the tsb

Alignment, and or other worn front end parts. Tire pressures, or even brake caliper drag.