Have a 2005 super crew with 22,000 miles. Problem is when starting from a dead stop like at a light I get a clunk or thud from the rear of truck, once in a great while its a double clunk/thud. The truck has a LS rear. It happens on on a straight start and while turning but only from a dead start. I don't get a shutter at any time. It does not do it in reverse. When I encounter the noise the truck has already moved foward about 6 to 12 inches. The dealer has no idea but is going to look at it again. Any ideas ? Thanks for your input in advance.

 

Sounds like a dry slip yoke. Try that first. Mostly happens to 2wd, but I've seen it in 4x4, too.

 

Sounds like my symtoms. Subscribing

 

A friend of mine has an 05 lariat that did the same thing. He had the dealer replace his driveshaft and it fixed the noise. They changed a bunch of parts in the rearend and still had the noise. They finally agreed to change driveshaft and the noise hasn't happened since. He had it changed back in 05 still no clunk.

 

Oh god the dried slip yoke again lol j/k didnt fix my problem

 

I have an 05' king ranch 4x4 and it's doing the same thing. I would like to know the remedy for this fix as well. I was thinking of replacing the LSD with an aftermarket unit. Any help would be appreciated.

 

i have an 04 and have the same problem. what i have done so far was jack the rear end up and see if it does it then. It will not do it when i shift into gear, so u-joints out of the picture, and wont do it when i stand on the brakes and give it gas. Only when i let of the brakes and start from a stop. I occasionally get a thump once and up to a couple times but not in reverse. When i had it on jacks, i grabbed the rear wheel and tried lifting and moving the tire up and down and side to side. i found that i can move the wheel up and down slightly with a little clunk noise. This shows me that my axle bearings may need to be replaced. Also on the back of one brake backing, i noticed like the signs of a dried liquid, possibly diff fluid. i checked the fluid and it was a little low. So what i have come up with is that proabably my axle bearings are going bad, allowing the axle to move ever so slightly back and forth when put under a load of starting from a stop, causing the axle to move enough to allow the axle seal to leak slightly. I am currently researching on what i need to replace them before i tear into it. So i will let you know. If it was the slip yoke, it should do it if you shift back and forth from drive to reverse. You might want to look at this.

 

cost me $40 per drive shaft to fix it at the dealer.........

they take the drive shafts out, lube the slip yokes, put them back................ fixed

 

definitely check the slip yoke or u-joints

 

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.