My '05 FX4 SCrew has a shudder when accelerating from a dead stop. The dealer says that "it is not bad enough to try and find, just keep driving it and see if it get worse". I don't particarly like that answer.
This is not the "clunk" or "bang" that some have when accelerating from a turn or after slowing down, it is only when you start from a dead stop.
It is not a motor shudder because if you powerbrake the truck to about 1500 rpm there is no shudder at all.
if you have a limited slip differential then I would venture to guess that it is the LS cluth packs shuddering. Mine did it too, the harder I launched (or starting off with heavy load) the more pronounced it was. My dealer also told me it was not bad enough, and then told me it was vibration from my Bassani exhaust.
I went to another dealer and they replaced the LS clutches and it has been smooth-as-silk ever since.
Yes my friends '04 Supercrew 4x4, did the same thing. Taking off from a parking lot turning onto the highway, shuddered the rear end then it quit when the truck got straight agian. Ford replaced the clutch packs, his was a 3.73 L.S.
I had a shudder from a dead stop on my '05 Scab, the dealer did the slip yoke grease TSB. This helped for a week or two but the shudder eventually started again and seemed to get worse. The dealer replaced the drive shaft and the problem appears to be fixed.
My 05 Super Cab F-150 FX4 4x4 with the 3.73 LS rear axle also has the clunking noise. The dealer looked at it today and said there was a TSB for it. They ordered a shim kit for the rear axle so hopefully that will fix the problem. Mine mainly did the loud clunk noise from a dead stop.
Well the truck is at the dealer now and they just called to say that they need it overnight as they ordered parts (shim kit) to fix the problem. We will see. The only good thing is that I am burning thier gas in a loaner.
other possibly is its slip yoke - theres TSB for it.. it need to be grease slip yoke.
Yoman, they already tried that on mine. They said that the only thing left to do is the shim kit. Sad to say that all these brand new vehicles need shim kits or to keep the slip yoke lubricated every month. But that is the way that everyone is making them anymore, build'em to let them break then crush and buy new.