Is it possible that the springs slap and make a clunk noise on take off and or slowing down. On the lower spring there is like a 1" gap with a plastic bushing on top of lower spring. On take off the axle will slap up or twist and lower spring against the other springs casuing noise?

 

There is a TSB on that clunk.

Something about the slip yoke and driveshaft splines that need special grease.

My '10 XLT 4.6, 4x4 doesn't have it. 1 pc driveshaft.

 

If it is the bump just before you come to a complete stop and just when you get rolling, then it is probably the slip yoke on the end of the drive shaft. As mentioned, ther is a TSB for warranty service if you are still in warranty. My dealer did mine and it is smooth now. I have no idea what it cost if you are out of warranty. The slip yoke bump is not a big concern, just annoying. They should lube them properly at assembly.

 

Mine had never done that, so they must lube them properly at the assembly plants now.

 

It's something with the driveline, our 2010 with the 2 pc driveshaft did it and we took it in and they put some teflon coating to fix it

 

Teflon grease is what they use on the slip yoke.

 

I've had this TSB done and the issue is coming back.