Right cam pulling out of sprocket flange

[jaredclark]

Hi
We have a 2005 explorer. The rear tensioner broke. We pulled the engine replaced all tensioners guides and chains. Got all timed right. Started the engine right up idled for about 45 seconds then started running rough and stalled. Checked compression on both banks.
Drivers was fine. Pass had zero compression. Found all three exhaust valves bent. Because the rear camshaft sprocket had pulled out of the cam tube. So the cam timing was now off and the lobes are not ridding on the rockers( the cam is shifted forward). So we got another cam off eBay. Installed it today. THE SAME thing happened. It ran for about a minute. Started running ins rough. We shut it down quick. Checked compression. Same none on the passenger side. Pulled the valve cover to find this cam did the same thing it is shifted forward and pulled out of the sprocket. Has anyone had this happen? What did we do wrong?
Thanks

 

[Tshaw88]

Did you take pictures of the cam shaft and sprocket after it bent the valves? When you installed the camshaft bolt did you use the hold down tool from the timing kit? And did you reuse the old bolt or did you get a new one? That bolt is tty and MUST be replaced because it stretches when torqued.