On my '04 cc/lb F-250 6.0 FX4 with 262000 miles, when it hits any bumps in the road it sounds like there is a bag of wrenches rattling under my front end. It only rattles at the bump. It doesn't continue as you drive down the road. It seems once you pass the bump and the weight resumes onto the axle the rattle instantly stops. I even drove around with the hubs locked and the rattle remained. The truck drives well, ball joints are tight, and it doesn't wander at all.
Any ideas or things I could look at?

Thanks in advance!

 

loose shock bolts?

 

Check the sway bar end links and the bushings. Pretty common.

 

I check it out tomorrow. Thanks!!

 

Tap your catalytic converter(s) as well just in case.

 

I looked over the bushings and they look decent. I took the weight off the axles when i inspected. I think my needle bearing may be shot on the passenger side. I can wiggle that axle around pretty easy. This looks a little more complicated to fix compared to the bushings.

 

Did you check the end links as well for the sway bar?

 

Yup. I believe I checked them all. The axle in the picture I can physically move an 1/8" in any direction. There's even a plastic seal that has worked its way out. I'm guessing that I shouldn't have that much slop with that axle.

 

Did you check to see if you do have a bag of wrenches stashed underneath?

 

Now that you say that, I am missing a few from my work bench!!

 

I had clunk noises that was solved by new u-joints. They were rusted and the caps broken off.

 

Well this morning I decided to finally tear apart the truck and try to find this annoying rattle. The hub is in good shape. The tire doesn't wobble at all. I found that the u joint was shot. Some I replaced it and reassembled everything and took it for a drive. It still rattled but only half as bad.
I did notice that I can still wobble the yoke assemble slightly as it goes into the back of the wheel/hub bearing. Do you guys think that the bearing is also bad even though the tire doesn't wobble?

Thanks!

 

Well I replaced the sway bar bushings, not that I thought that they were bad but sometimes looks can be deceiving. And they were only $15.
It still rattles!
The drag link bushings looked good too.
There is a fair amount of movement/slop from the axle that protrudes into the wheel hub assembly. Maybe the hub is bad but it's not showing the typical signs of being bad. I would rather not spend another $120 guessing that the problem may be fixed but I think it's my next option.

 

If you have the locking hub removed, the axle stub will have play/slop in the outer end. I serviced my truck's front end last year with everything new. Stub shafts, wheel bearings, u-joints, seals and ball joints. I still had a lot of play in the stub shaft. Turned out the locking hub itself was worn out.

 

I had a suspicion that it could have been the locking hub too. I removed it complete and took it for a test drive and the noise was still there. I think my only other choice is to replace the hub assembly.