I know this is an Cadillac group (I have an XLR-V so I'm usually chatting it up in that sub-forum), but I imagine that there are probably some members here who have run into this problem for their Escalade...

I have an 05 Yukon Denali with OE GM 20's on it and have the exact problem that TSB 05-02-32-008B describes. Based on what I gather, my truck has the 670 gearbox and not the 680 that this TSB recommends.

I've made four trips to two dealers and they refuse to perform the TSB.

Evidentally my Denali was built with 17's originally, and the 20's were added later (this may or may not be true, I have no idea - I bought the truck new off the lot with the 20's)... therefore they claim that the "tires larger than stock size" and therefore this TSB doesn't apply.

These are the OE GM wheels that are an available option with the OE Goodyear rubber on them. Its actually as this photograph shows:



Anyone have any advice on how to get this resolved?


Subject: EI06002 - 670 Gear Box Power Steering Pump, P/S Performance Concerns #05-02-32-008B - (07/18/2007)



Models: 2003-2006 Cadillac Escalade, Escalade ESV, Escalade EXT

2003-2006 Chevrolet Avalanche, Suburban, Tahoe

2003-2007 Chevrolet Silverado Classic

2007-2008 Chevrolet Silverado, Suburban (2500 Series Only)

2003-2006 GMC Yukon, Yukon Denali, Yukon XL

2003-2007 GMC Sierra Classic

2007-2008 GMC Sierra, Yukon XL (2500 Series Only)




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This bulletin is being revised to add model years and models. Please discard Corporate Bulletin Number 05-02-32-008A (Section 02 -- Steering).


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Condition
Some 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. This concern can be aggravated by worn tires, low tire air pressure, low power steering pump pressures, and tires larger than stock size.

Correction
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.

Perform the "Power Steering System Test" found in SI. Make any necessary repairs based on system diagnosis.
1.1. 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. A Field Product Report should be submitted - refer to Corporate Bulletin Number 02-00-89-002D.

1.2. FOR 1500 SERIES VEHICLES ONLY - If diagnostics did not lead to any repair, this concern is a normal operating characteristic.

If the vehicle is equipped with a 670 gear box, replacing it with a 680 gear box may increase the customer satisfaction.
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 BULLETIN. The vehicle is not equipped with a 670 gear box.
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
Part Number
Description

88965542
Power Steering Gear

26025709
Union Fitting

26001594
Inlet O-ring Seal

Contact SEMA...www.SEMA.org - If memory serves me correct the Magnusson-Moss Act legally requires an OEM (i.e. their Dealership) to make their TSB's - whether or not there are aftermarket products on a vehicle unless they can prove that those aftermarket items can be proven to have SPECIFICALLY caused a (ANY) specific OEM part to fail. That's what SEMA is for...to protect both the aftermarket manufacturers and the vehicle owners from unfair advantages that will be taken by the OEMs...even when their Dealership(s) sell aftermarket items on their retail vehicles (i.e. upsized rims, larger tires, rpgraded leather interiors, sunroofs, simulated convertible tops, etc, etc, etc)
YOU have your rights. Good luck in getting them taken cars of. Get SEMA to send you a copy of the Magnusson Moss Act, read it, and drop the bomb on your local stealership!!!

Try another dealership, some are much better than others, I hear many problems from my GMC customers about service. :(

Do you have the original tires and wheels? If so, put them on and see if you have the same problem.
Did you inspect the steering gear as described in the bulletin to see which model gearbox you have?
You'll notice there is a line there that says 1.2. FOR 1500 SERIES VEHICLES ONLY - If diagnostics did not lead to any repair, this concern is a normal operating characteristic
Which means bulletin or no, they won't do anything anyway.

Changing tire and wheel sizes and configurations does indeed directly affect the power steering system. I have seen it many times. Sadly, if there is too much resistance on the power steering system no amount of factory parts replacement will fix it.
If it is a factory authorized tire/wheel combination then some dealer might help you. It sounds like you might have to keep looking for one that will.
I know a guy that works just North of Dallas/Fort Worth, but I am not sure he could help you either.
Plus, I think that is a long way from Houston.