my brother inlaw has a 97 z71 350 engine, he has a noise that sounds like draging a chain, his front diff was way low on fluid so I filled that for him but he says the noise is still there and it will make a poping noise. any ideals? thanks in advance

mark

 

If I had to guess off the top of my head, I would say it's in the transfer case, considering it has a chain in it.

 

Could be the timing chain too. How many miles are on the vehicle?