First Order Driveline Vibration May Be TCC Sensitive - keywords prop shaft shudder

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

When diagnosing 1st order driveline vibration concerns, it is possible that the rear axle drive pinion could contribute to the condition. If following SI Vibration Diagnosis procedures leads to Document ID #1579470 for checking Differential Pinion Input Shaft Runout, also check for drive pinion pitch line runout. The pitch line is an imaginary line drawn around the pinion gear, connecting the centers of the gear teeth. If there is runout in the pinion gear teeth, or if one or more teeth are incorrectly machined, a 1st order driveline vibration could result.

Note: This condition would be more noticeable on vehicles with low mileage or after a ring gear and pinion replacement and may be more noticable with tcc applied.

Runout in the pinion gear teeth, or an incorrectly machined pinion gear tooth, can cause variation in backlash between the ring and pinion gears. If the variation is large enough, it could cause a vibration. Check for this condition by measuring ring gear to pinion backlash once for every tooth on the pinion (usually 12, 13, or 14 teeth). Variation in backlash of .001" or more on adjacent teeth and .002" overall can cause this condition.

Service procedures in SI are pending.

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.