Went to a quick lube shop and they said the plug on my rear diff had a good amount of metal shavings on it but the fluid looked good...is it normal to have shavings but the fluid to be good?

FYI..I bought the truck a year ago

 

I do not recommend a quick lube shop for working on, or advising on, mechanical systems like rear ends, transmissions, engines, brakes, etc. I use them for routine oil changes and scheduled maintenance items and nothing else. Take your other problems to the best, most experienced mechanic you can find. It'll save you time and money in the long run and will get the proper repair done correctly the first time.

Recently, I had one of these quick lube shops perform the 60k scheduled maintenance on my wife's sedan. During the servicing procedure, they misdiagnosed a leaking water pump as a leaking radiator cap and installed a new cap. They were pleased as punch and proudly announced they had found and fixed the problem. However, the following week I had to add coolant when the heater quit blowing hot air. At that time, I realized they had misdiagnosed the problem and took the vehicle to an "old head" who runs a local radiator repair shop. Within 30 seonds of looking into the engine compartment, the radiator guy said "the water pump is leaking." He said that most pepole do not realize where the water is coming from on these engines because the serpentine belt is slinging the leaking coolant onto to the radiator cap. He said "I see it all the time on these engines."

So, beware who you believe. Take the time to talk to an experienced mechanic, preferably a truthful one, if you can find one.

 

Metal shavings are to be expected, to a certain extent. How much is a good amount? I changed my rear diff fluid this past summer. The plug had some shavings on it, nothing to get excited about though. The gears looked great, so I replaced the gasket, reinstalled the cover and filled her up and she has been running fine since.