Strategy Based Diagnostics
Review the system operations in order to familiarize yourself with the system functions. Refer to Transfer Case Disassembled View , Transfer Case Description and Operation , and Rear Drive Axle Description and Operation . All diagnosis on a vehicle should follow a logical process. Strategy based diagnostics is a uniform approach for repairing all systems. The diagnostic flow may always be used in order to resolve a system condition. The diagnostic flow is the place to start when repairs are necessary. For a detailed explanation, refer to Strategy Based Diagnosis .
Visual/Physical Inspection
- Inspect for aftermarket devices, which could affect the operation of the vehicle. Refer to «Checking Aftermarket Accessories»(ref-644726-S15551717792014072300000) .
- Inspect the easily accessible or visible system components for obvious damage or conditions, which could cause the symptom.
- Inspect for the correct lubricant levels and the proper viscosities.
- Verify the exact operating conditions under which the concern exists. Note factors such as vehicle speed, road conditions, ambient temperature, and other specifics.
- Compare the driving characteristics or sounds, if applicable, to a known good vehicle and ensure you are not trying to correct a normal condition.
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom
- «Diagnostic System Check - Vehicle»(ref-644698-S03753758692014072300000)
- «Noisy in Drive»(ref-644780-S12954277642014072300000)
- «Noisy When Coasting»(ref-644780-S30810068072014072300000)
- «Intermittent Noise»(ref-644780-S09533972542014072300000)
- «Constant Noise»(ref-644780-S27642614012014072300000)
- «Transfer Case Leak Diagnosis»(ref-644780-S38500556752014072300000)
Transfer Case Leak Diagnosis
| Cause | Correction |
|---|
| DEFINITION: A visible indication of an external fluid leak from the transfer case. Review the Symptoms - Transfer Case and perform the necessary inspections. See below for suggested diagnostic method(s). |
| Special Tools GE 28431-6 Fluorescent Oil Dye GE 28428-E High Intensity Black Light Kit For equivalent regional tools, refer to Special Tools . Fluorescent Dye Method Add GE 28431-6 Fluorescent dye to the transmission or transfer case to determine the source of the leak. Operate the vehicle. Inspect for the presence of dye within the oil leak using the GE 28428-E High Intensity Black Light Kit. A presence or non-presence of dye within the oil leak will indicate which component is the source of the leak. Powder Method CAUTION: Do not clean using brake cleaner or other reactive solvents as these solvents can damage rubber gaskets, seals and bushings. Thoroughly clean the suspected leak area using a rag. Apply an aerosol type leak tracing powder to the suspected leak area. NOTE: Do not drive the vehicle on the freeway as this will splatter oil inhibiting leak diagnosis. Operate the vehicle for 15-20 minutes under city driving conditions until normal operating temperatures are reached. Shut OFF the engine. Inspect the suspected leak area. Trace the leak path through the powder in order to find the source of the leak. |
| Drain plug or fill plug leak | Inspect for dirty, worn, scored sealing surfaces, or missing drain and/or fill plug sealing washers. Replace as required. |
| Restricted or damaged ventilation hose assembly | Replace the ventilation hose assembly, as required. |
| Leaking at the transfer case left side weep hole A transmission oil leak at the transfer case weep hole area is caused by the transmission right side drive shaft seal. A gear oil leak at the transfer case weep hole area is caused by the transfer case input shaft front (inner) seal. | Replace components as required. If the leak is transmission or O-ring related, do not replace the transfer case input shaft seals. |
| Leaking at the transfer case right side weep hole A transmission or gear oil leak at the transfer case right side weep hole is caused by the input shaft seal located in the rear extension housing. | Replace the input shaft seal. |
| Leaking ATF at the right side axle shaft-to-intermediate shaft bearing location | Replace the intermediate shaft seal located in the rear extension housing. |
| Leaking at rear output shaft area A leak at rear output shaft area is caused by either the rear output shaft seal or the rear output shaft housing O-ring seal. | Inspect and replace the rear output shaft seal as required. The O-ring is not serviceable on AAM transfer case. |
| Leaking at transaxle assembly-to-transfer case interface A transmission oil leak at the transmission-to-transfer case interface may be caused by the transmission-to-transfer case o-ring seal. A transmission oil leak at the transfer case weep hole area is caused by the transmission right side drive shaft seal. A gear oil leak at the transfer case weep hole area is caused by the transfer case input shaft front (inner) seal. | NOTE: If the leak is transmission or O-ring related, do not replace the transfer case input shaft seals. Identify the type of oil leak. Replace components as required. |
| Case half seam leak AAM | Disassemble and replace the transfer case-to-rear extension housing O-ring seal. |
| Leaking through case | Inspect for a cracked case. Inspect for case porosity. |
| CAUTION |
|---|
| Do not clean using brake cleaner or other reactive solvents as these solvents can damage rubber gaskets, seals and bushings. |
| NOTE |
|---|
| Do not drive the vehicle on the freeway as this will splatter oil inhibiting leak diagnosis. |
| NOTE |
|---|
| If the leak is transmission or O-ring related, do not replace the transfer case input shaft seals. |
Transfer Case Leak Diagnosis
