JARblue

Definitely sounds like just need to grease the rear axles. When driving, you say it feels connected to the gas pedal. Is it more like its related to the slack in the drivetrain? When you give it gas, the drivetrain is going to slide back causing the click, but it also happens when you just let off the gas sometimes because the engine brake will cause the drivetrain to slide forward causing another click. This is what I experienced.

If so, the thread SouthArk linked is the one you want. It has all the info you need. I would start with some moly lube on the joints near the wheel hub. See the FSM diagram. If that doesn't work or you notice the adjusting cap is loose, you might consider replacing it per the instructions in the link. Be sure to read the entire thread for details on the amount and type of washers to use with a castellated nut.

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