I am new to this forum and have found a lot of good info so far. I have a 2004 Super Crew FX4 with a 5.4L automatic trans. The truck has 46,000 miles on it.

I am having a problem when I accelerate from a stop. I got a clunk that sounds like it is coming from the rear. Sometimes it clunks once and sometimes twice. After i drive for a while(20-30 miles), the clunk gets quieter, but I can feel a shudder. This only happens when taking off from a dead stop. Sometimes when it is real bad it actually feels like I ran over a pot hole or something.

It has been to the dealer five times. They have replaced the ring and pinion, the spyder gears, the limited slip clutches, the carrier bearings, and have lubed the splines on the driveshaft three times. Nothing seems to take care of the problem.

I noticed that many people have the same problem. Has anyone found a fix for this? Any help would be greatly appreciated.

 

The clunk and the shudder are 2 different/distinct symptoms...

Typically, you'll feel a shudder when turning while taking off. That is usually a symptom of issues with your LS clutch packs? Do you have LS (limited slip) rearend? Does it only shudder when taking off while turning?

As far as the clunk, that would be a worn our slip yoke. The TSB for this issue calls for either greasing the splines with teflon grease (if no metal shavings are present), or replacing the entire driveshaft (if metal shavings are present). Likely, your slip yoke has worn, and no amount of grease is going to fix it. It MAY temporarily ease the severity of it, but it will come right back. You need to push them to replace the whole driveshaft. Do you have an extended warranty? When did they first try to fix the clunk?

I had to have my driveshaft replaced at about 25,000 miles due to the clunk on stopping & takeoff. No probelms since then.

 

I have this problem also, but mine is the shutter or feels like going over rubble strips on the road. It seems to only do this when taking off from a stop and turning. No clunk just shudder. It has 15K on it. Is this a common problem with these trucks? Any insite will help before i take it in for service thanks again.

 

Chas, check your u-joints. Also, if you have a LS differential, add a bottle of friction modifier.

 

I did a search on this site very helpful BTW, and found this is a bigger problem than i thought. Ive owned a couple of trucks with LS and never had this issue until now. I bought this truck used with 15k on it and to have this problem already scares me. Its under warrenty shouldnt i just have them add the modifier?

 

I have this exact problem. It is intermittent so it took me a while to figure when it occurs. I get a shudder in my truck when I take off from a dead stop and am turning. This is the only time I feel the shudder, however, it doesn't occur every time under these circumstances (meaning it doesn't always shudder while turning from a dead stop). I have a 4.6 L 99 f150 screw with 120K. I have recently had my transmission fluid/filter changed, brakes done and plugs and cables replaced. Should I also check my U-Joints and add the modifier? Since this is just annoying, I may let it go for awhile until I have some $$$, will this result in larger problems if I do so? Thanks in advance!

 

Wow, this thread speaks to me..

I have a 2005 F-150 Supercrew 5.4 Lariat w/ 3.73 LS rear end. 26k miles.

I get the same exact symptoms.

Stopped at a light, turning right (or left)... Light acceleration, slight shudder from the rear end...

It feels like the wheels are slipping on some gravel or a wet road, but as we all know, stock f-150's can't spin their wheels

It is definitely present. I have been meaning to take it into the dealer, as it is still under warrantee.

 

05 F150 FX4 78K miles.

Mine did it new, maybe 2,000 miles.
Dealership took a peek and lubed it, went away until.

Now (78K miles), Dealership took a look, lubed it and said there were some metal shavings but not that bad. They said I'd probably need a new Drive Shaft in a couple years. They said there wouldn't be a catastrophic failure but just more consistent clunking down the road.

I'm kinda pissed, this should not have happened at 2K miles or
78k miles. I would think that major part should last much
longer than that.