vibration/rumble 1000-1500 rpm

bmeyers · November 7, 2006

I have a 2004 GMC Sierra Denali with awd and quadrasteer. It has 35,000 miles. I am having a problem at around 40-45 mph and at 1000-1500 rpm. It is basically the same as driving over rumble strips in the road. It happens consistently while I am driving and then coast for a moment and the rpm's get to around 1100. I will lightly get on the gas at that rpm and the whole truck will vibrate like I was going over rumble strips. If I get on the gas hard it does not happen. If I hit the tow button it also does not happen. It only happens when I am light on the gas and in that rpm range. Any clues? I am bringing it in for service on 11/08 and would like to give the tech a heads up on a possible cause. It seems to only happen in fourth gear but that is really the only time I am at that rpm in that speed range (40-45 mph and 1000-1500 rpm's).

GM-Tech · November 7, 2006

Sounds like you might have the following going on. Seen quite a few of these and they act just as you describe...

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Subject: 4L60-E/4L65-E/4L70-E Automatic Transmission/Torque Converter Clutch (TCC) Shudder, Water in Transmission (Repair Transmission and Seal Cowl Area) #05-07-30-017B - (02/17/2006)

Models: 2004-2006 Cadillac Escalade Models

2004-2006 Chevrolet Avalanche, Silverado, Suburban, Tahoe Models

2004-2006 GMC Sierra, Yukon Models

with 4L60-E (RPO M30), 4L65-E (RPO M32) or 4L70-E (RPO M70) Automatic Transmission

--------------------------------------------------------------------------------

This bulletin is being revised to add additional model years, the 4L70-E transmission and clarify usage of Labor Operation B9758. Please discard Corporate Bulletin Number 05-07-30-017A (Section 07 -- Transmission/Transaxle).

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Condition

Some customers may comment on a shudder condition at approximately 64-80 km/h (40-50 mph) when the TCC engages.

Cause

This condition may be caused by water in the automatic transmission fluid (ATF). Water may enter the transmission by dripping from the cowl area onto the handle of the transmission fluid level indicator.

Indications of water in the ATF may include:

• Visible water in the oil pan

• A milky white substance inside the pan area

• Spacer plate gaskets that appear to be glued to the spacer plate, valve body or case

• Rust on internal transmission iron/steel components

Important: For vehicles suspected of having a leaking transmission oil cooler that would cause contamination of the transmission fluid with coolant, the following check should be performed before deciding to replace the radiator.

• Remove the surge tank cap and examine the coolant for signs of contamination with transmission fluid (the coolant will have a milky, not clear appearance).

• If the coolant has a normal, clear appearance, the radiator should not be replaced.

• The cooler can also be tested by following the Coolant System Leak Test procedure. Do NOT replace a radiator without verifying that the transmission oil cooler is leaking.

Correction

Two steps are required to repair the vehicle. First, repair the transmission and second, seal the cowl area to prevent repeat water contamination of the ATF. This bulletin is focused on repairing the second step.

Transmission Repair

Important: If water or coolant is found in the transmission, the following steps must be performed:

Remove the transmission. Refer to the appropriate SI procedure.

Disassemble and inspect the transmission. Refer to Unit Repair Automatic Transmission - 4L60-E/4L65-E or 4L70-E.

Important: If water or coolant is found in the transmission, the following components MUST be replaced.

• Replace all of the rubber type seals.

• Replace all of the composition-faced clutch plate assemblies including the band.

• Replace all of the nylon parts.

• Replace the torque converter.

• Thoroughly clean and rebuild the transmission, using new gaskets and oil filter.

• Flush and flow check the transmission oil cooler using J 45096. Refer to Corporate Bulletin Number 02-07-30-052D or newer - Automatic Transmission Oil Cooler Flush and Flow Test Essential Tool J 45096 TransFlow .

Seal the Cowl

Open the hood and install fender covers.

Remove both air inlet grille caps by pulling up on the caps.

Loosen the sheet metal screws, one on each end of the air inlet grille panel.

Remove the four attaching clips running along the edges of the center air inlet grille panel.

Measure and cut a piece of 7/64 inch hose, P/N 14033569 or equivalent, 1.27 meters (50 inch) long.

With an appropriate sharp cutting tool, cut down the center of the hose, splitting the hose into a C shape, allowing the hose to be installed over the cowl seam.

Apply a thin layer of Weather-strip Adhesive, P/N 12345097 (in Canada use 10953479) or equivalent, into the center of the cut hose.

Lift up on the air inlet grille panel in order to expose the cowl area metal edge.

Place the 7/64 inch hose over the cowl metal edge between the two inner fender brace bolts. Make sure that the hose is long enough to be retained by the two most outer air inlet retaining clips.

Push back, towards the windshield, on the air inlet grille and install the four retaining clips.

Push back, towards the windshield, on the air inlet grille and tighten the end screws.

Tighten

Tighten the sheet metal screws to 2 N·m (18 lb in).

Install the two air inlet grille end caps.

Close the hood.

Place the vehicle in an area that a water test can be performed.

Turn OFF the vehicle.

Open the hood.

Place a shop rag over the top of the transmission dipstick.

Close the hood.

Spray and/or run water over the windshield and cowl area for three minutes.

Open the hood.

Inspect the shop rag for signs of water leaking on top of the transmission dipstick area.

• If NO water is present, close the hood and NO additional repairs are required.

• If water IS present, repeat steps 1-20.

Warranty Information

Important:

• DO NOT submit a transmission repair (labor and parts) on Labor Operation B9758.

• Use the appropriate transmission repair labor operation in conjunction with B9758.

For vehicles repaired under warranty, use:

Labor Operation

Description

Labor Time

B9758

Install 7/64 Hose - Cowl Water Deflector

0.5 hr

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

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bmeyers · November 7, 2006

Thanks for the quick response. I will print this out when I bring it to the shop on Weds. Is this something that would totally be under warranty since my truck has leass than 36,000 miles?

Sounds like you might have the following going on. Seen quite a few of these and they act just as you describe...

-----------

Subject: 4L60-E/4L65-E/4L70-E Automatic Transmission/Torque Converter Clutch (TCC) Shudder, Water in Transmission (Repair Transmission and Seal Cowl Area) #05-07-30-017B - (02/17/2006)

Models: 2004-2006 Cadillac Escalade Models

2004-2006 Chevrolet Avalanche, Silverado, Suburban, Tahoe Models

2004-2006 GMC Sierra, Yukon Models

with 4L60-E (RPO M30), 4L65-E (RPO M32) or 4L70-E (RPO M70) Automatic Transmission

--------------------------------------------------------------------------------

This bulletin is being revised to add additional model years, the 4L70-E transmission and clarify usage of Labor Operation B9758. Please discard Corporate Bulletin Number 05-07-30-017A (Section 07 -- Transmission/Transaxle).

--------------------------------------------------------------------------------

Condition

Some customers may comment on a shudder condition at approximately 64-80 km/h (40-50 mph) when the TCC engages.

Cause

This condition may be caused by water in the automatic transmission fluid (ATF). Water may enter the transmission by dripping from the cowl area onto the handle of the transmission fluid level indicator.

Indications of water in the ATF may include:

• Visible water in the oil pan

• A milky white substance inside the pan area

• Spacer plate gaskets that appear to be glued to the spacer plate, valve body or case

• Rust on internal transmission iron/steel components

Important: For vehicles suspected of having a leaking transmission oil cooler that would cause contamination of the transmission fluid with coolant, the following check should be performed before deciding to replace the radiator.

• Remove the surge tank cap and examine the coolant for signs of contamination with transmission fluid (the coolant will have a milky, not clear appearance).

• If the coolant has a normal, clear appearance, the radiator should not be replaced.

• The cooler can also be tested by following the Coolant System Leak Test procedure. Do NOT replace a radiator without verifying that the transmission oil cooler is leaking.

Correction

Two steps are required to repair the vehicle. First, repair the transmission and second, seal the cowl area to prevent repeat water contamination of the ATF. This bulletin is focused on repairing the second step.

Transmission Repair

Important: If water or coolant is found in the transmission, the following steps must be performed:

Remove the transmission. Refer to the appropriate SI procedure.

Disassemble and inspect the transmission. Refer to Unit Repair Automatic Transmission - 4L60-E/4L65-E or 4L70-E.

Important: If water or coolant is found in the transmission, the following components MUST be replaced.

• Replace all of the rubber type seals.

• Replace all of the composition-faced clutch plate assemblies including the band.

• Replace all of the nylon parts.

• Replace the torque converter.

• Thoroughly clean and rebuild the transmission, using new gaskets and oil filter.

• Flush and flow check the transmission oil cooler using J 45096. Refer to Corporate Bulletin Number 02-07-30-052D or newer - Automatic Transmission Oil Cooler Flush and Flow Test Essential Tool J 45096 TransFlow .

Seal the Cowl

Open the hood and install fender covers.

Remove both air inlet grille caps by pulling up on the caps.

Loosen the sheet metal screws, one on each end of the air inlet grille panel.

Remove the four attaching clips running along the edges of the center air inlet grille panel.

Measure and cut a piece of 7/64 inch hose, P/N 14033569 or equivalent, 1.27 meters (50 inch) long.

With an appropriate sharp cutting tool, cut down the center of the hose, splitting the hose into a C shape, allowing the hose to be installed over the cowl seam.

Apply a thin layer of Weather-strip Adhesive, P/N 12345097 (in Canada use 10953479) or equivalent, into the center of the cut hose.

Lift up on the air inlet grille panel in order to expose the cowl area metal edge.

Place the 7/64 inch hose over the cowl metal edge between the two inner fender brace bolts. Make sure that the hose is long enough to be retained by the two most outer air inlet retaining clips.

Push back, towards the windshield, on the air inlet grille and install the four retaining clips.

Push back, towards the windshield, on the air inlet grille and tighten the end screws.

Tighten

Tighten the sheet metal screws to 2 N·m (18 lb in).

Install the two air inlet grille end caps.

Close the hood.

Place the vehicle in an area that a water test can be performed.

Turn OFF the vehicle.

Open the hood.

Place a shop rag over the top of the transmission dipstick.

Close the hood.

Spray and/or run water over the windshield and cowl area for three minutes.

Open the hood.

Inspect the shop rag for signs of water leaking on top of the transmission dipstick area.

• If NO water is present, close the hood and NO additional repairs are required.

• If water IS present, repeat steps 1-20.

Warranty Information

Important:

• DO NOT submit a transmission repair (labor and parts) on Labor Operation B9758.

• Use the appropriate transmission repair labor operation in conjunction with B9758.

For vehicles repaired under warranty, use:

Labor Operation

Description

Labor Time

B9758

Install 7/64 Hose - Cowl Water Deflector

0.5 hr

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

© Copyright General Motors Corporation. All Rights Reserved.

--------------------------------------------------------------------------------

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GM-Tech · November 7, 2006

Yes, that would be a warranty repair for sure.

bmeyers · November 7, 2006

Thanks for all of your help. You are the man and I really do appreciate your input.

booster · March 6, 2007

I actually pulled the trans dipstick on my 2005 Suburban and the tranny fluid looked like Pepto Bismol when I was having this same problem a few days ago.