Hello again all, I have a E99 F350 7.3L 4x4 I know some or most of you have already probably replaced this part and or pulled a front axle shaft out. So here is my question...In the pictures provided you can see what I think everyone is calling a "Dust Seal" and as you can see it is bad and making a very terrible noise when i hit a bump...I was wondering what parts I would need to replace this seal? I tried looking it up and just get lost in all of the other things....I have found write-ups for the axle being removed while changing ball joints but none by it self to just replace this seal. If someone could please help me out and let me know what I need to replace this seal it would be greatly appreciated

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I would be looking elsewhere for whatever noise you're hearing. Its highly unlikely that the dust seal is causing a terrible noise. I would check ball joints, sway bar bushings, shocks/mounts, track bar, steering linkage/tie rods, etc. That dust seal doesn't serve much purpose, and on most trucks its in alot worse shape than yours is.

But to answer your question, you could follow the steps in my writeup (link below) except you won't need to disconnect the tie rod end.

2004 F250 Ball Joint Replacement

 

Grab ahold of the outer axle (the one that goes into the back of the hub/knuckle). If you can excessively move it up and down and side to side within the hub/knuckle assembly, then your noise is probably coming from the hub bearing assembly.

 

I have checked all the other bushings and my ball joints are new the mechanic said the wheel bearing was still good I can move that shaft up and down and I think its because of that seal....but I'm not sure.....I'm gonna try what you said and move the shaft on the wheel bearing side and see what happens

 

Looks like the grease zerk in the upper ball joint has been hitting the U-joint.

The dust seal failing is not going to cause the axle movement, it really doesn't do much more than attempt to keep some of dust and dirt out of the axle tube. It doesn't really seal as much as it just fills the gap. The new seal design might do a better job but doesn't work with the older axle housing.

I would be looking into the condition of the needle bearing in the back of the hub assembly, the hub assembly bearings (wheel bearings) and the condition of the U-joint and the outer axle shaft where the needle bearing rides. Even when everything is tight and in good shape the axle shaft still has some up and down movement. My zerks do come close, but they never hit.

Anytime you pull the axle shaft it is a good idea to replace the knuckle seal and hub assembly O-ring. I also change the dust seal if I am in there. You will need to buy or make a seal driver to install the knuckle seal onto the axle shaft and set it into the knuckle when you install the axle shaft.

 

that seal is a joke i put a brand new one on my f250 when i did u joint on pass side 100 miles later and it was seperated in 2 pieces and dangling on the axle just like the one i took off totally worthless imo

 

As mentioned, that seal has nothing to do with axle movement.

To replace the dust seal you have to remove the wheel bearing assy, so you can inspect that yourself, also check the needle bearings and be sure to replace the big knuckle seal, as mentioned above.

Is the play on the "wheel side" of the axle u-joint, or the "differential side"? Could it be the bearings failing in the front differential?

 

I checked it when I got home from work today...the play is on the wheel side of the axle joint. Does this mean that the needle bearing is bad? if so how are is it to replace it?

 

That's definitely a possibility.

If you're taking it apart to replace that dust seal, you'll have the wheel bearing assy removed and its on the backside of the assy. There's talk about that in the write up I linked above, with a separate write up that covers the needle bearing.

See: 2004 F250 Needle Bearing Replacement

If you happen to find that your needle bearings are shot, be sure to check the outer shaft of the axle. It could be damaged as well.

 

Yes I made sure I checked for play in the other side as well and found a little bit of movement but not much. Im gonna grab 2 of everything and throw new bearings and seals in. and Hopefully thats my problem because I cant seem to find anything else. Thanks again.

 

Hey guys just figured I would give you an update. I replaced the Driver side Needle Bearing and no noise as of yet *knock on wood* Im glad you guys pointed me to it because the bearing I took out was pretty much completely frozen. The pass side isnt making any noise so Im going to replace it anyways so it better to be safe than sorry. Thanks again guys!

 

Good deal! Hope it works out for you. Good call on replacing the other side too.

 

I broke my front drivers side outer axle, axle broke flush with the hub/inner side by nut and I got it apart up to taking the hub assembly off..cant figure out how to pull the knuckle assembly and inner axle out? please help

 

Easiest way is with an air chisel on the backside of the knuckle seal. Get a pointed chisel and grind it down flat so it doesn't punch through the seal easily. Keep the chisel moving around the perimeter of the seal (it is metal), and it takes about 15 seconds to get the shaft out. Alternative is to use a punch and hammer, or a prybar against the u-joint. These take much longer and are much more work

No need to remove knuckle to pull axle.

 

Ok, thanks a lot will try that today.. I am also replacing the knuckle u-joint and dust/spindle seal, would you recommend doing anything else why I have it apart? I have 130,000 miles on the truck