4wd Problem

[Volucris]

I have a problem I hope you can all help me with. I have a 2007 1500 classic, crew, 4WD, LS. I drove abount 16 miles the other day on a rocky snowy mountain road in 4WD low range. When I got back to the hiway I stopped, put it in neutral, and shifted into 2hi. The transfer case shifter is on the floor.

 

Something stuck. I could no longer put it on 4wd lo or hi (or at leat the indicator light wouldn't come on). When I put it in 2wd and drove on the hiway, there was a lot of mechanical drag until there was a god-awful clunk from under the vehicle, and then it drove fine. The clunk definitely sounder like something that was stuck releasing.

 

I took it to the dealer and got the "we can't make it happen here so we can't fix it if we can't tell it's broke" response. Do you all have any idea what this might be? The truck only has 14,000 miles on it, so this is pretty dissapointing.

 

Another thing. When I'm driving in 4lo, there is quite a bit of noise. Is that normal?

 

Thanks,

 

Volucris

[jrrod2004]

I have a problem I hope you can all help me with. I have a 2007 1500 classic, crew, 4WD, LS. I drove abount 16 miles the other day on a rocky snowy mountain road in 4WD low range. When I got back to the hiway I stopped, put it in neutral, and shifted into 2hi. The transfer case shifter is on the floor.

 

Something stuck. I could no longer put it on 4wd lo or hi (or at leat the indicator light wouldn't come on). When I put it in 2wd and drove on the hiway, there was a lot of mechanical drag until there was a god-awful clunk from under the vehicle, and then it drove fine. The clunk definitely sounder like something that was stuck releasing.

 

I took it to the dealer and got the "we can't make it happen here so we can't fix it if we can't tell it's broke" response. Do you all have any idea what this might be? The truck only has 14,000 miles on it, so this is pretty dissapointing.

 

Another thing. When I'm driving in 4lo, there is quite a bit of noise. Is that normal?

 

Thanks,

 

Volucris

 

I would tell them to pull the transfer case housing and check for metal shavings, as well as the transmission pan itself, speak to the Service Manager, if not call Chevrolet and tell them as well as the dealership you want to speak to the DVM (District Vehicle Manager) cause you are a paying customer. Here is some info you can read and 'suggest' to the dealership:

 

 

 

 

Transfer Case Clunk in 4LO

Cause

 

Correction

 

DEFINITION: During acceleration or deceleration, a clunk is heard or felt in the transfer case while in the 4LO range only.

 

Review the Symptoms - Transfer Case and perform the necessary inspections.

 

High/low planetary carrier assembly

1. Inspect for the following conditions:

• Excessively worn planetary gears

 

 

• The pinion gears loose in the planetary carrier

 

 

• The input gear for missing thrust washers or excessive thrust end play in the carrier

 

 

• Excessively worn range collar engagement teeth on the carrier

 

 

• Refer to

Cleaning and Inspection .

 

 

 

Replace the high/low planetary if any of the above conditions are found. Refer to Transfer Case Disassemble and Transfer Case Assemble .

 

Annulus gear

1. <LI type=1>Inspect the annulus gear to front case fit for any looseness. Refer to

Cleaning and Inspection .

Replace the front case half if the annulus gear is loose. Refer to Transfer Case Disassemble and Transfer Case Assemble .

 

Range sleeve

1. <LI type=1>Inspect the range sleeve engagement teeth for excessive wear. <LI type=1>Inspect the range sleeve to mainshaft splines for excessive wear.

    

2. Replace the range sleeve if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .

    

Transfer Case Clunk in 2HI Only

Cause

 

Correction

 

DEFINITION: During acceleration or deceleration, a clunk is heard or felt in the transfer case while in the 2HI mode.

 

Review the Symptoms - Transfer Case and perform the necessary inspections.

 

Incorrect fluid level or incorrect fluid

1. <LI type=1>Inspect the transfer case for the correct fluid level. Refer to

Transfer Case Fluid Replacement . <LI type=1>Inspect the transfer case for the correct type of fluid.

Flush the transfer case and fill with the correct fluid, if required. Refer to Transfer Case Fluid Replacement .

 

Excessive clearance between the slip yoke and the rear output shaft

1. <LI type=1>Inspect for the following conditions:

• Worn slip yoke splines

 

 

• Worn rear output shaft splines

 

 

 

Repair or replace the following components if faulty:

• Replace the slip yoke, if required. Refer to

Propeller Shaft Replacement - One Piece and Propeller Shaft Replacement - Two Piece .

 

 

• Replace the rear output shaft, if required. Refer to

Transfer Case Disassemble and Transfer Case Assemble .

 

 

 

Excessive clearance between the slip yoke and the rear bushing

1. <LI type=1>Inspect for the following conditions:

• Worn rear bushing

 

 

• Worn slip yoke bushing journal

 

 

 

Repair or replace the following components if faulty:

• Replace the slip yoke, if required. Refer to

Propeller Shaft Replacement - One Piece and Propeller Shaft Replacement - Two Piece .

 

 

• Replace the rear bushing if worn. Refer to

Transfer Case Output Shaft Seal Replacement - Rear .

 

 

 

Worn high speed teeth on the range sleeve

1. <LI type=1>Inspect for the following conditions:

• Worn high speed teeth on the range sleeve

 

 

• Worn or missing input gear thrust washers

 

 

• Refer to

Cleaning and Inspection .

 

 

 

Repair or replace the following components if faulty:

• Replace the range sleeve if worn. Refer to

Transfer Case Disassemble and Transfer Case Assemble .

 

 

• Replace the thrust washers, as required. Refer to

Transfer Case Disassemble and Transfer Case Assemble .

 

 

 

Rear output shaft bearing outer retaining ring

1. <LI type=1>Inspect for the following conditions:

• Proper installation of the rear output shaft bearing retaining ring

 

 

• Excessive wear or damage to the retaining ring groove in the rear case half

 

 

 

Repair or replace the following components if found faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .

• Properly install a new rear output shaft bearing outer retaining ring.

 

 

• Replace the rear case half if the retaining ring groove is excessively worn.

 

 

 

They may throw this at you as well:

 

 

Subject:Clunk Noise When Shifting Into or Out of 4WD Lo or Neutral - keywords grind harch #PIP3408B - (09/07/2006)

 

 

 

 

Models:2003-2007 Chevrolet Avalanche, Silverado, Suburban, Tahoe

 

 

2002-2007 Chevrolet Trailblazer

 

 

2002-2007 GMC Envoy

 

 

2003-2007 GMC Sierra, Sierra Denali, Yukon, Yukon XL

 

 

2002-2007 Hummer H2

 

 

2006-2007 Hummer H3

 

 

with Four Wheel Drive

 

 

 

 

This PI is being updated to clarify the concern. Please discard PIP3408A.

 

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

 

 

Condition/Concern:

Clunk or grind noise when shifted into or out of 4LO or neutral more noticeable with the engine running.

 

 

Recommendation/Instructions:

This is a normal operating characteristic by design due to low range being a non-synchronized gear.

 

To reduce the clunk condition, turn the engine off and then shift to 4LO.

 

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.

[Volucris]

Thanks for the help.

 

Volucris