Internal Transfer Case Noise - keywords grind growl rattle

This PI was superseded to update model years and Recommendation/Instructions. Please discard PIP3467C.

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

Engineering is conducting an investigation on any type of internal transfer case noise and needs your help in isolating customer concerns.

If the abnormal noise can be isolated to the transfer case using conventional methods, please fill out the attached questionnaire prior to contacting the Technical Assistance Center for further instruction and diagnosis.

Note: Remember do not operate the vehicle in unlock (4hi) mode on the hoist as damage to the planetary gear set may result due to an over speed condition.

Questionnaire for Noise or Vibration

Standard Package (2.64:1 ratio, two-speed transfer case)

Also

Stock Tires - Yes / No - Make: ____________ Type: ____________ and Size: ____________

1. How many transfer case noise complaints are being reported for this vehicle? If more than one, please fill out each section for each transfer case noise complaint.
2. Has the customer's concerns been duplicated by the dealer/technician?

Yes, please proceed with Dealer Noise Summary, then Customer Noise Summary.

No, please proceed with Customer Noise Summary.

Dealer Noise or Vibration Summary

1. Does the noise complaint occur while driving the vehicle or while shifting the transfer case?

While Driving, proceed to the Driving Section. While Shifting, proceed to the Shifting Section.

2. Was the vehicle tested on the dealer hoist? If Yes, was the vehicle in Low Range? If Yes, please conduct a vehicle road test before filling out this summary, because the t/case is expected to make noise due to Low Range Gearset.

Driving Section

1. What was the transfer case mode during the observed noise complaint?
2. What was the transmission gear?
3. What was the Road Environment during the observed noise complaint?
4. What was the road surface type?
5. What was the Throttle Position during the observed noise complaint (Please check all that apply)?

Tip-In (Accelerating at speed, highway passing)

 

Tip-Out (Decelerating at speed with no brake)

 

Light Throttle Acceleration

 

Moderate Throttle Acceleration

 

Heavy Throttle Acceleration

 

Braking

 

Coasting (Deceleration without using the brakes)

 

Other (Please Describe):

 

 

6. What was the Vehicle Speed (MPH) range during the observed noise concern?
7. What was the Steering Wheel Position during the observed noise complaint?
8. Was the complaint felt or heard or Both?

If felt, where was it felt?

If heard, from what location i.e. front, rear?

9. Please Describe the Noise sound and location:

IF heard or felt during a transfer case shift continue

1. What Mode was the transfer case shifting from and then to?
2. Was the vehicle Stopped or Rolling at the time of the shift?
3. Please Describe the concern i.e. clunk, grind:

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.