Here it goes. My sister's car died so she borrowed my 79 K10. Then she calls me one day and tells me the truck is knocking, thought it was the motor. Motor is fine, only knocked when rolling. I first thought it was the U-joints, but I wasn't that lucky. Took the pumpkin cover off a while ago and teeth came out w/some black/metallic lube!! The axle is ruined right?? What does it take to cause this damage?? I came to find out that other people drove my truck but no one admits to abusing my K10. Damage like this only happens under abuse, right?? Ok, boys and girls, I'm poor and don't have a lot of time; please give me some ideas on what to do about fixing this truck. It is a 79 w/12 bolt rear, I'd like to know if I can throw in an axle from a 90's truck in there. How about one from a 2wd truck, can I just swap axles(5lug to 6lug)?? Maybe it's time to get some real axles(3/4 or 1 ton). I'll hit the boneyards in the mean time. TIA. Zo out.