I have had posi units on and off over the years. Some made noise and some didn't. It isn't unreasonable to think that under certain conditions you might actually hear the components (springs, gears and clutch packs) moving around inside the housing under different power application scenarios (e.g. turning corners). The one post that mentioned a mechanic friend who told him about there being less clutch material in the replacement pack might be telling the truth. If Ford is experiencing problems with its buyers complaining about the original clutch packs making too much noise, it might make sense for them to put an assembly in there that is less clunky (e.g. fewer clutch plates or less surface area). It would not be the first time such a compromise was made.

In the old days if you had a big motor and wanted to make sure your posi locked up you could actually force in an extra clutch disk into some of the differential assemblies and make sure that sucker locked up under power. If you weren't real careful you could end up with a situation that negated the differential part of the equation be effectively locking both axles together with too much friction tying the two sides together via the clutch pack. Lots of fun. You turn a corn and the outside wheel sort of chirps around the corned as the torque builds up on the axle and releases as the tire spins round.

As for lubricating drive shafts to eliminate clunking....hmmm...excuse me if I can't quite swallow that one as a long term solution. Clunking is some sort of mechnical issue and squirting some grease into some assembly in an attempt to fix it doesn't make a lot of sense long term. Would you agree?

I have my fingers crossed. I have 1300+ miles on my 04 SCREW and no clunks, vibrations or whines (build date July 04).

TV

 

Truck is in shop right now, now they are trying to tell me it is my dual exaust causing it...... OMG, back to yelling and screaming..... will let all know. They have had it for 2 days straight now.

 

FWIW: the noise I heard from my rear end when I backed out my driveway and turned to go down the street, I'd hear some clunking noise coming from the passenger side rear wheel. I took it in to my dealer, and had the head master mechanic look at it for me, and he lubed the slip yoke as mentioned before, then added a friction modifier to the differential fluid. I have no more clunk, so I'm happy. Hopefully, it will be a lasting fix.

 

Mine went into the shop this morning for the clunking/jerking shift and for squeaking brake(s).

I've got 16,500 + miles on mine - it's done this since the beginning, but it wasn't that noticeable until I was hauling a new gooseneck trailer. My last 2 F150s had limited slip and high end gear; but they were only 2WD - not 4WD so I didn't know that what I was feeling was the difference between 4WD versus 2WD.

It will stay overnight .... hopefully tomorrow I'll have an answer. They don't even know what's making the brakes squeak... hhhmmm....

 

Day 4:

Well, replacing the drive shaft did not work, they ordered new clutch packs. I will keep y'all posted

 

The whole thing sounds screwy to me. They've got so many of these trucks vibrating and clunking...it's like the dealers don't tell Ford what they are trying to fix it.. If they are then Ford's engineers must be guessing. You would think they would pull 15-20(or 200 of them, whatever it takes) of these problem trucks back from owners and analyize(sp) the problem. Sounds like they are shipping driveshafts, clutch pacs and rears all over the country in a shotgun effort to find the problem..

Anyway you cut it, it's adding cost to the trucks on the lots, maybe not this year, but they get even eventually for their own mistakes..

Mine's still smooth as glass at 1500.... thankfully..

 

I have the same problem

 

OK guys - Ford had my truck for 1 week. They replaced the drive shaft and clutch pack. Truck drives great now, no problems!

THANK GOD - It only took 3 months to fix!

 

Scott,


Sounds as if the clutch pack is the answer then wouldnt you say. From the previous page you said they did the drive shaft and it did not work. I have the same problem and the squeeking brakes so I am getting ready to take mine in just trying to see what to push for. Thanks for the update.

 

Actually, i went in for drive shaft, but they ordered clutch pack while it was in there. I guess they put drive shaft in, and it did not work, so they went to plan b. who knows.... but no problems now!

 

Do you all have Limited slip? My 03 King Ranch did the same thing and it had limited slip. My 04 does not and so far I am having no problems. I also noticed that the dealer was not ordering many limitied slip trucks for inventory. Is this a coinkydink or is the dealer on to something?

 

Yeah it only involves the limited slip. The regular rear has no clutch pak.

 

Well the parts came in. going in on Friday morning for surgery. Will let you guys know the outcome. They're gonna change the clutch pack & grease my shaft. oooh! I can't wait.

 

Just got back from the dealer. I was smiling all the way home. No more clunk.
They greased the driveshaft, replaced the clutchpacks, and added an updated friction modifier. It drives as smooth as a baby's ***.

 

Thanks for the update! Got appointment Monday to get mine fix