Well here's the deal, I have a 97 F-150 4x4 and have had this irritating clunk since I got it a couple of years ago. It happens from a stop and go. I had everything from the u-joints to the rear end checked. My dealership and I have finally came up with the answer that its my slip yoke that enters the transfer case. Everytime we re-grease it with Ford's special TF grease it goes away for a while than its back. It seems the grease keeps working out the back of the slip yoke via a little air hole. I have used numerous types of metal adherent greases to try and solve the problem but the clunk keep coming back after a month of driving or so.
What I need to know is if anybody else has had this problem?? The dealership told me to try another slip yoke(new one) and see what happens. I also heard that GM sells a grease product for a similiar problem they had with there 1500 series trucks.

What should I do......can anybody give me some advise. I love the truck but ready to sell if the problem persists!

thanx, D

 

Same clunk on my 97, standard 5-speed. Had it for about a year, and no problems so far. I thought I would just live with it, but now that I think of it....Can you actually pull the slip yoke when under the truck? Maybe I will look into this when the snow stops!!!

 

blocksbikes,

i have the same truck as you with the same problem. i grease and it's good for about a month and then comes back. since i used teflon grease though it will clunk after the first few stops but after that it must "lube" itself and it's fione the rest of the drive.

 

Well lubed it again about a month ago and its back. looks like i will try a new slip yoke and see what happens. This is getting really annoying and maybe its time to set a stick of dynamite under it.......just joking. Will update when I get the new yoke on for a month or so.