No Movement Forward or Reverse - keywords 4476 4479 axle broken case differential forward front grind noise park transfer transfercase
| Subject: | No Movement Forward or Reverse |
| Models: | 2004-2006 Cadillac SRX |
| 2005-2006 Cadillac STS |
| Equipped with AWD |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
No forward or reverse movement. There may be noise from either the transfer case and/or front differential area of the vehicle when trying to move the vehicle.
Recommendation/Instructions:
Inspect the front differential and front drive axles for damage. If either front axle shaft is disconnected or if the ring and pinion has broken internally, collateral damage may occur to the transfer case. These vehicles are equipped with open differential style transfer cases and operating them with one output shaft "disconnected" will cause the pinions in the transfer case to go into an over-speed condition causing noise. This would also be the case if something was disconnected in the rear drive system. The pinions are straight cut design and will exhibit this type of noise during an over-speed event. Continuous operation in an over-speed event can cause serious internal transfer case damage.
Do not replace a transfer case for noise with no movement unless physical damage is found inside the transfer case. Repair the axle concern first and then drive the vehicle to verify whether any abnormal noises still exists.
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.
