Picking Up My New Truck! Have A Few Questions

Nobleman · May 18, 2008

hey all,

will be driving in an Onyx Black 08' Sierra Denali by the end of the week!

been going through the forums and there are a TON of great lookin trucks on here!

I'm just puttin together some questions to ask when I pick up the truck:

what I have in mind from searching the forums:

- TSBs, I'm assuming that when a new vehicle leaves the factory it's updated with all the latest TSBs. Correct, or no?

The two I'll be asking about regardless are the 07+ Tranny TCM, TSB for the 6spd auto:

" Subject: 6L80 Automatic Transmission - Hesitation, Lack of Performance, Difficult to Obtain Downshifts (Reprogram TCM) #07-07-30-030 - (11/21/2007)

Models: 2007-2008 Cadillac Escalade, Escalade ESV, Escalade EXT

2007-2008 GMC Sierra Denali, Yukon Denali, Yukon Denali XL

with 6L80 Automatic Transmission (RPO MYC)

Condition

Some customers may comment that the vehicle has a hesitation or lack of performance when attempting to accelerate with moderate throttle apply in the 56-113 km/h (35-70 mph) range. They may also comment that it is difficult to obtain transmission downshifts in the same 56-113 km/h (35-70 mph) range. "

- and I've read that there is a potential oil leak on GMT900 trucks?

does anybody have a link to the TSB for either of these? Don't see them in the tech wiki

- aside from those, last questions have to do with tires and wheel offset

tires: 305/40/22, will they rub in any way on the NBS Sierra Denali's (at stock height)? i'm pretty sure i've read that they are fine on all other new GM trucks, just not sure about the 07+ SD..somebody has to have tried them? 285/45/22 are ideal, but really want the widest tires possible

TPMS: do I have to get OE sensors from GM to give to my shop for the aftermarket wheels going on, or are generic ones compatible with the truck?

wheel offset: the ET for the 2007+ is 28-40, the wheels i'm getting come in 15mm or 38mm offset. so the 15mm would be a problem, 38mm would be perfect? still kind of confused on offsets.

any help is appreciated, thanks guys!

jrrod2004 · May 18, 2008

To answer your concern, the vehicle will leave the factory with the latest that they have available in the supply line, (Does not mean that it will be the most updated part/programming, etc), however it is the dealership's job to go over the truck when they do the PDI (Pre Delivery Inspection)

jrrod2004 · May 18, 2008

I could post every little TSB on the GMT-900s, but the problem is time, I dont have alot of it like I used to....

jrrod2004 · May 18, 2008

Here are some of the latest GM TSBs that address the Oil Leaks:

Service Information

2008 GMC Truck Sierra Denali | Sierra, Silverado (VIN C/K) Service Manual | Document ID: 2085948 #PIP4321B: Oil Leak at Rear of Engine - keywords 4.8 5.3 cover crank crankshaft gasket housing LC9 leaking LH6 LMF LMG LY2 main pan porous seal shaft - (Mar 25, 2008)

Subject:Oil Leak At Rear Of Engine

Models:2007-2008 Chevrolet Express, Silverado, Tahoe

2007-2008 GMC Savana, Sierra, Yukon

Equipped with a 4.8 or 5.3 V-8 Engine RPO codes LC9 LH6 LMF LMG LY2

This PI was superceded to remove the direct engineering contact information. Please discard PIP4321A.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

A dealer may encounter a customer concern of a engine oil leak. Leak may be found at the rear of the engine.

Recommendation/Instructions:

Complete the current SI diagnostic for engine oil leaks. If a rear of engine oil leak has been verified (many times there has been multiple repair attempts with no resolution to rear of engine leak) it is possible to have a porous crankshaft. The oil leak described in this PI will originate from the rear of the crankshaft (Where a pilot bearing would be located).

If a porous crankshaft has been verified, the crankshaft will need to be replaced. Complete the current SI repair procedures and evaluate repairs.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

jrrod2004 · May 18, 2008

Service Information

2008 GMC Truck Sierra Denali | Sierra, Silverado (VIN C/K) Service Manual | Document ID: 2063520 #PIP3343A: Possible Engine Oil Leak Due To PCV Freeze-Up - keywords 4.8 5.3 6.0 6.2 air ambient body cold dip dipstick fill freezing intake inlet L33 L59 L76 L92 LH6 LC9 LM7 LMF LMG LQ4 LQ9 LR4 LY2 LY5 LY6 start - (Feb 11, 2008)

Subject:Possible Engine Oil Leak Due to PCV Freeze-up

Models:2006-2008 Cadillac Escalade

2002-2007 Chevrolet Avalanche, Express, Silverado, Tahoe Classic

2002-2007 GMC Savana, Sierra, Yukon Classic

2007-2008 Chevrolet Avalanche, Express, Silverado, Tahoe

2007-2008 GMC Savana, Sierra, Yukon

Equipped with the 4.8 5.3 6.0 and 6.2 V-8 engines.

This PI was superseded to update model years and part number. Please discard PIP3343.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

A vehicle may be brought to the dealer with a customer concern of an oil leak after a cold start. This concern will only occur in areas with extremely low ambient temperatures.

During diagnosis the dealer may find the oil leak is coming from the dipstick tube. PCV freeze-up may induce an oil leak from the dipstick tube.

Recommendation/Instructions:

If an oil leak from the dip stick tube has been verified, and the PCV system has signs of freezing, replace the oil fill cap. There is an updated vented oil fill cap to repair this concern.

Order a new Vented Oil Fill Cap part number 12589430 from GMSPO.

Install the vented oil fill cap, clean and dry the PCV hoses, and evaluate the repair.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

jrrod2004 · May 18, 2008

Service Information

2008 GMC Truck Sierra Denali | Sierra, Silverado (VIN C/K) Service Manual | Document ID: 2049261 #PIP4127A: Perceived Fluid Leak at Rear Seal - keywords prop shaft yoke - (Jan 17, 2008)

Subject:Perceived Fluid Leak at Rear Seal

Models:2008 Chevrolet Avalanche, Suburban, Tahoe

2007-2008 Chevrolet Silverado

2007-2008 GMC Sierra

2008 GMC Yukon, Yukon XL

Equipped with Magna Transfer Case RPO Codes NQF, NQG, NQH

This PI was superceded to update models and years. Please discard PIP4127.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

Some dealers may notice during PDI inspection that a small amount of transfer case oil is visible around the rear output seal.

Some dealers have recently replaced seals for this condition. These seals that were thought to be defective at PDI. The seals were actually not defective.

Recommendation/Instructions:

All transfer cases arrive at the plants with a shipping plug inserted into the rear output. This shipping plug goes through the rear output seal. As the shipping plug is removed a small amount of oil that has built up in behind the plug is released. While some fluid leakage does occur at shipping plug removal, this condition should not be diagnosed as a defective seal.

If some seepage of residual oil is apparent at the rear output seal during PDI inspection the technician should carefully wipe it off and dry the surface with a clean shop cloth. If seal leakage is apparent after being thoroughly cleaned to a point where it drips onto the ground then the seal should be replaced before the customer takes delivery.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

jrrod2004 · May 18, 2008

Service Information

2008 GMC Truck Sierra Denali | Sierra, Silverado (VIN C/K) Service Manual | Document ID: 2034071 #PIP4153A: Engine Oil Pressure Sensor Leak - keywords 07 block drip LBZ LMM seal sealing - (Oct 26, 2007)

Subject:Engine Oil Pressure Sensor Leak

Models:2007 Chevrolet Express, Kodiak, Silverado

2007 GMC Savana, Sierra, Topkick

Equipped a 6.6 Duramax Diesel Engine RPO codes LBZ or LMM

This PI was superseded to update Recommendation/Instructions. Please discard PIP4153.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

The customer concern may be an engine oil leak. The dealer may find the oil leak is coming from Oil Pressure Sensor.

Recommendation/Instructions:

If a leak at the oil pressure sensor has been verified, reseal the sensor using the process below.

Replace the oil pressure sensor gasket (sealing washer) during the repair.
Properly clean and degrease the engine block surface and the oil pressure sensor threads. Use cleaner part number 12377981 (in Canada 10953463) or equivalent.
Dry the area with compressed air.
Use pipe sealer part number 12346004 (in Canada, 10953480) on the threads and the flange of the oil pressure sensor.
After the flange and the threads of the sensor have sealer on them reinstall the sensor and torque to 41 Nm.
Let sealer dry 4 to 6 hours and evaluate the repair.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

jrrod2004 · May 18, 2008

The sensors will have to be mounted with the aftermarket rims, to the best of my knowledge, no aftermarket solution is compatible with the factory TPMS....but I have been proven wrong, take it with a grain of salt

jrrod2004 · May 18, 2008

And by the way: Welcome to GM-TRUCKS.COM

Nobleman · May 19, 2008

WOW, definitely more than I could have asked for! Thanks a lot man

with the tires, i'm gonna see if my dealership has some tpms sensors when i go in, then order some 305/40/22s at the custom shop and hope for the best! worst comes to worst i believe just a 2"-2.5" front leveling kit will give the clearance needed if they do rub a bit.

slimjim2525 · May 19, 2008

WOW, definitely more than I could have asked for! Thanks a lot man

with the tires, i'm gonna see if my dealership has some tpms sensors when i go in, then order some 305/40/22s at the custom shop and hope for the best! worst comes to worst i believe just a 2"-2.5" front leveling kit will give the clearance needed if they do rub a bit.

2" lift should give you enough clearance.