Front end popping noise on my '05

This just started about a week ago. My '05 is making a popping/knocking noise when accelerating through 1st and 2nd gear then it quits. This happens while driving straight. Turning doesn't seem to cause it like a bad CV axel. I'm about to take it in for a diagnosis but thought I'd check here first. The truck has 270k miles with everything in the front end original. Thanks in advance for any ideas!

 

Well, after trying to get a better idea where the noise is coming from it now sounds like it could be towards the middle or rear of the truck. I rolled my windows down to try to get a better listen. It seems to do it right between 5 and 10 MPH and only seems to do it while it's in gear. I put it in neutral a few times approaching stoplights and it didn't do it but would when in gear. The rear end has new bearings. I'm stumped.

 

Have you checked the carrier bearing and u joints for play?

 

I haven't. I'll take a look at them tomorrow.

 

There's about 1/2" of play in the center support bearing and I have a feeling this may be the problem. It's the original with 270k miles on it. I put a go pro under the truck while driving it but I'm still having a hard time pinpointing the clunking noise. Should there be any play at all in the center support bearing?

 

It should move a little a half inch sounds about right. If the rubber is dry rotted though it couldn't hurt to replace it anyway.

One other thought the slip yoke may need to be cleaned up and greased.