drive shaft clunk
 

ok so, my truck just started doin this 2 days ago. when i go from reverse to drive i get a clunk ( no lerch forward) same from drive to reverse, if i look under the truck i can see my drive shaft moving almost a full turn. is this normal?

mine clunks too i also get a nasty noise out of the rearend wen coasting, or flooring it in reverse

ya thats exactly wat im talkin about

now im really curious, i think its the gears but they are new, mayb the u-joint, i hope, its cheaper

wouldnt have anything to do with the trani?

i dont think so mines new

Backlash in the ring and pinion. A certain amount is normal, but I'm not sure what the typical amount should be. I kind of doubt it is a full turn unless the tires are moving a fair amount. My detroit locker has a lot of backlash (it is suppose to) and it turns nearly a little over 1/4 of a turn on the driveshaft, which is considered a lot.

Sounds to me like a bad u-joint or the infamous slip-yoke bump.

i just tryed again id say its 5/8 of a turn

i know this is a stupid question and i appoligise, but when u say u-bolt u mean my ubold holding my leafs to my axle?

u joint..... ill change that tomorrow

mark and remove the driveshaft and check both u-joints, check and see how much the pinion moves with the wheels on the ground, it shouldnt move more than 1/8 of a turn id say. grab the driveshaft on either side of the slip shaft and see if you can turn the two pieces against eachother, if you can, go to the ford dealer and buy the TSB repair kit for the driveshaft, it comes with some awesome grease and new clamps to use to fix it

I get that same clunk from time to time. I just thought it was my money trying to run away

what if it doesnt move

I agree with Brian, reminds me of a backlash issue.
Had the same issue with my old s-10 which was fixed when I traded it in :ponder:

thank you so much man this really helps. ill keep u posted.

then it is fine..your truck is 2wd isnt it? if so you dont have to worry about this, its supercab 4x4 only

I can almost guarantee it is your rear driveshaft u-joints.. get them replaced..

i check the u joints they seem to be fine, im still getting that clunk any more ideas?

have you checked the slip shaft?

no i have not

why dont you try the ideas posted in this thread before you ask for more ideas? id highly suggest you check the slip yoke before you go into and further in depth diagnosis

lol
I love it when people ask for advice, get a bunch of cheap (often free) ideas and keep asking for more advice. People can advise you all you want but we can't 'magician' your truck better! ;)

The slip yoke is a very very very common noise/thump maker. I still think if you are getting a lot of driveshaft movement (rotationally) without the tires budging at all, there may be something else going on. But you start with the free/cheap stuff.

at this point if it is the slip shaft, i wonder what it will take to get him out of his computer chair and actually go buy the fix kit LOL

tsb repair kit
 

what comes in tsb repair kit Imay try this on mine