I have a 94 F350, four door, 4x4, IDI. When I engage the manual locking hubs and put the truck in 4wd there is a klunking sound that is coming from the drivers side wheel. It is a continuous klunk-klunk-klunk while driving. If I speed up the noise gets "faster" and there is a bad vibration. I took the hub and spindle apart and changed the small bearing inside the spindle and it made no difference. I think the locking hub might be bad, the locking hub and the small bearing inside the spindle seem to be the only things holding the axle in place while it is turning. The axle seems to be flopping around inside the spindle and axle tube making the noise and vibration. Is it possible the hub is bad, and is there a way to check before just throwing money and parts at it. Appreciate the help.

 

You check the front driveshaft, wheel universal joints right? A whooped joint will make noise.

 

I checked the U joint, it is tight, not even a teeny bit of play, drive shaft looks ok, it does not appear to be damaged in any way, truck has not been in an accident that would have damaged drive shaft. I replaced the bearings in the hub and the small bearings and seals that are inside the spindle that the outboard axle runs through. The klunking noise and vibration are still there. It looks like the inboard axle that goes inside axle tube and into pumpkin is moving around inside the tube and causing the noise and vibration. Not sure what else it could be, everything from the U joint outboard to the lug nuts appears to be tight and in good or new condition. It leads me to believe that the problem is inside the pumpkin. Is there a bearing or some sort of mechanism that helps hold/align the inboard axle on the differential end where the splines meet the gears inside the differential that could be worn or bad? I have a parts diagram of the axle and it is hard to tell by looking at the pics what exactly is inside of it. The axle is a Dana 60 mono beam if that helps. Thanks again.

 

Now i have seen, more than once u joints that appear tight and good, but still are bad. Each u joint cup has needle bearings, and if they are rusted, the cap will essentially be bound up with rust if you will, giving the tightness and illusion of the joint being okay. I suggest, take em apart, and check em. If you problem lies in the differential, i think you would know. Inside the pumpkin, is the diff. On each side of it are carrier bearings. Outside of those, going toward the outside of the axle tubes, are seals on each side inside the axle tube that retain the gear oil for the diff. If a bearing was bad, causing the axle to flop, the axle in turn would positively wipe out the seal in no time flat. So if you have no oil coming out of you axle tubes, rule that out. The next thing in line after the seals is the seals and bearings in the spindles that you checked.
Another thing to check is the cardan joint on the front axle driveshaft right out of the transfer case. It looks like 2 u joints right next to eachother. Between them, is needle bearing assembly. I have one on my 95, that i just replaced last week. When in 4wd, i would get a grinding with vibration, that i would feel in the steering wheel. Sounded like hell and took me awhile to find it as all the parts were tight and looked okay. The funny thing is the parts to rebuild this part, were $80 plus i redid the front driveshaft joints while i had it out. So it was like $140 in parts plus my time. Napa could get me a brand new bolt in driveshaft with cardan joint and u joints, ready to go, for $210. Should went that route cuz that joint was kinda a pain to rebuild. Next time.

 

Jack that front wheel up off the ground and spin the wheel and listen for the noise. then engage the hub and spin again to isolate the problem.

 

I have spun the wheel while in the air and am not able to replicate the problem. I tried running the truck in 4wd with the drivers side hub disengaged and the noise is not present. I am not sure if that would rule out the cardon joint near the t-case output shaft or not. There appears to be little or no oil coming from the axle tube indicating the oil seal is gone. If the carrier bearing were bad in the diff would I be able to hear it when the hubs are not engaged and the t-case is engaged making the axles spin with no power to the hubs. I have tried this and there is no noise. The noise is only evident when both hubs are engaged and truck is in 4wd. I also checked the cardon joint just now and there is a little play in it, I am going to take it out and replace it or put new u-joints in it and see if that helps.

 

I wish I could come over and check that out. Whats the oil looklike in the front axel? Pop that cover off and see if any parts are broken in the diff.
How about having some one hold one side while you turn the other side by hand and check for play.

 

Oil in front diff was milky and grey, deifinitley needed changed. There were no metal shavings or chunks in the oil. I think I may have found the culprit. The centering yoke, that is in between the two u-joints that are attached to the transfer case end of the front drive line has some play in it. I am not sure how to describe how much other than to say quite a bit. I imagine more than enough to cause a vibration and noise. I took the driveline to the parts store so I could make sure I got the right one and the guy behind the counter had the exact same thing go wrong on his ford a couple of days earlier, and he described to me the exact same noises and problems I was having, and he thought it was in the front diff or somewhere in the hub. Any how, the part will be here tuesday and when I get it installed I will post an update. Got my fingers crossed, but I am feelin pretty good abut this one. Thanks again for everyone's help.

 

I have had the same thing happen in the rear CV joint on my Bronco. It looked ok but was bad.

 

That my good man is the cardan joint that you located sloppy. When it went bad on my truck, it really would only make noise while accelerating. Spinning the driveline in air with no resistance to torque from the transmission/engine would not get me any noise. Good luck

 

So, I replaced the centering yoke that sits between the two U joints in the cardan joint, the vibration and noise is greatly reduced. The driveline needs to be totally rebuilt or a new one put in. I have neither the time or the money for either at this point. There are two pieces to the cardan joint and one is fairly easy to change out, the other requires cutting the old part off and welding a new one on and then re-balancing the driveline. I am going to run her like this for awhile. If anyone else out there hears a sound like the front axle is flopping around inside the axle tube, check your u-joints. I am relieved to know it is nothing to do with the front diff. I am VERY thankful for everyone's help. Long Live The Forum!