Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
Hello I will help you with your question,
How many miles on the truck and has the rear end ever had any service done?
Tires the same size all around?
The first thing I would do is get the cover off and inspect for debris, if no big chunks are found refill with the correct 75W-90 Synthetic Axle Lubricant and add the friction modifier if the label does not specify it has modifiers included.
Do several figure eights in a quiet parking lot and see how it performas after that.
If you still have problems the locker will need to be rebuilt.
Please let me know if you have further questions
Great, please let me know what I can do to help