well, my rear-end started clunking on my 97 f-150 4x4, 4.6L at around 85,000 miles. it got worse and worse as time went on. had the trans fluids flushed, and this did not resolve the problem. asked several mechanics, and they both told me it was probably the spline gears having play. thanks to the response of TROYK, i have resolved the problem. it was the slip-yoke in need of grease. i was skepticle of the resolution, but it worked. 30 minutes of work and the truck is like new. anyone with rear-end clunk should try this. my problem was most noticealbe from a dead stop. make sure to mark the axle with fingernail polish or paint before removal. make sure you put the axle back in the same position to make sure the driveshaft stays balanced. a big thanks to TROYK. i also read on 'Other drive trains' on this web site that the ford dealer ship replaced the rear gears, on a newer f-150 to no avail. try the $2 can of grease on the slip-yoke. thanks to for the responses.

 

Pretty cool

But, you should use the $25 teflon grease.... The lovely turquose goo

 

Thanks plug !

I am having the same problem in my 97 Expy (loud clunk).

You should get a digital camera and try to post some pictures on the steps to take to grease the slip-yoke....that will be nice

Saludos!!!

Una cerveza for you amigo