Rear End Noise 2005 Jeep Grand Cherokee

During deceleration at about 30mph and below there’s a loud ticking noise what sounds like from the rear. If I accelerate it seems to stop. Any ideas what this rear end noise could be?

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RESPONSE

• How to Diagnose a Noise

This is most likely coming from the rear differential. Specifically the pinion shaft bearings. Drain a little rear end fluid and look for the gear oil to has a shinny tint. You may also notice tiny metal flakes. This is from the bearings breaking down and will cause a rear end noise.

Once the bearings are replaced the differential bearing preload and gear backlash need to be adjusted to proper specifications.

 

• Install new collapsible spacer (1) on pinion gear and install pinion in housing.
• Tap pinion flange onto the pinion.
• Install flange washer and a new nut on pinion and tighten pinion nut until there is zero end-play.
• With a torque wrench and Flange Wrench C-3281 tighten the pinion nut to 285 N·m (210 ft. lbs.).NOTE: Do not exceed the minimum torque 285 N·m (210 ft. lbs.) when installing the pinion nut at this point.

• Measure pinion torque to rotating (1) with an inch pound torque wrench (2). Measure pinion torque to rotating frequently to avoid over over-crushing the collapsible spacer.Pinion Torque To Rotate is:
• Original Bearings: 1 – 2 N·m (10 – 20 in. lbs.)
• New Bearings: 1.7 – 4 N·m (15 – 35 in. lbs.)

If pinion torque to rotate is low, tighten pinion nut in 6.8 N·m (5 ft. lbs.) increments until pinion torque to rotate is achieved.

CAUTION: Never loosen pinion nut to decrease pinion bearing rotating torque. If pinion torque to rotating is exceeded a new collapsible spacer must be installed. Failure to follow these instruction will damage the axle.

Ring gear and pinion are supplied as matched sets. Identifying numbers for the ring gear and pinion are painted onto the pinion gear shaft and the side of the ring gear. A plus (+) number, minus (–) number or zero (0) along with the gear set sequence number (2) (01 to 99) is on each gear. This first number (1) the amount (in thousandths of an inch) the depth varies from the standard depth setting of a pinion marked with a (0). The next two numbers are the sequence number of the gear set. The standard depth provides the best teeth contact pattern.