So, I've been on here about an hour reading everything I can that came up in a search about rattles. Nothing specifically the same.....although, there were some 2wd trucks that sounded like they were the same.

From start up, no rattle. Sounds perfect. Forward only, doesn't rattle in reverse, but will rattle under load. Rattle gets "faster" as rpm's go up. Sounds like it's coming up from right underneath me. Engage 4H, no more rattle. Back to 2H, no rattle until the truck idles for a while, like at a stop light or if I shut it off and the truck sits for any length of time.

Any ideas? Am I looking at a transfer case issue?

 

Read through this thread and it should give you your answer.

https://www.f150online.com/forums/20...then-some.html

 

Thanks!

Edit: That was it. I was so sure it was something else, I skimmed through that topic the first time. When you suggested I read it, i did. . . .again. After looking at the diagram, I went out to the truck and checked the lines. Drivers side line, right at the wheel was completely disconnected. :o As you can see, I don't post much . . . . probably should keep it that way.

Thanks again for the help!

 

You are welcome.