A leak has developed (pic 1, pic 2) at the end of the front axle on the driver's side.

How serious is this? Is it hard to fix? Would it cause a major vibration?

Any input appreciated,
Thanks,

Bryan
2003 F350 SD 7.3L
253,000 miles and counting.

 

Seals are inboard next to the diff. You must remove it to replace the seals. This alone will not cause a vibration.

 

The vibration felt is like running over the ribs on the side of the road only a little less severe and without the noise. It's only happened a couple of times and immediately stops if I switch to 4 wheel drive. If I lift the truck and push the wheels in and out there is no play. I suspect the lockouts, but not sure. Speaking of the lockouts, when I priced them the parts store wanted to sell me a service pack to go with them. My Haynes manual says nothing about a service pack. Anyone know what's up with that?

 

I had a vibration like you are explaining and it was caused by the inner bearing that is on the hub assembly that the axle stub rides on. Unfortunately that bearing is non serviceable so I had to replace the entire hub assembly and axle end because I ran it to long like that and wore a groove in it. The way I found it was by lifting up the front end and while the hubs are unlocked I turned the wheel to the extreme left or right and spun the tire and heard the growling sound and saw that the axle was trying to turn cause of the friction of the bearing being locked up and grabbing the axle shaft.

 

He is right the bearing that the stub shaft rides on is bad, had the same problem. you can change the bearing but is really hard to get out. the new hub assembly is about 250$ each at auto zone the bearings are less than 10$ each at the dealer. most likely your stub shaft is also bad. you can change it but the dealer might try to sell you the whole axle shaft when you can buy just the stub shaft for 110$ the work isn't that hard i did both sides in half a day.

 

Ok guys, you've got me interested. I've got a loud growling noise coming from my right front area. I was suspecting the power-steering as it seems to occur when turning at <10 MPH. PS looks ok with no obvious issues. This thread may have just changed my mind on I.D.ing the gremlin.

Goes away or may be unnoticable while driving?
Mine also tends to occur while sitting still, in park, while idling.


Can someone feed me some more things on what to look for without having to tear down and inspecting the assembly?

 

If you are hearing the noise while the truck is sitting still than it's definatly NOT the front axle bearing. You have to be moving for that bearing to be rotating.

 

You guys have been a tremendous help and I do appreciate it. If the axle bearing is bad, wouldn't there be play as I push in and pull out on the top of the tire? ( after taking the weight off of course )

If it warms up enough today, I'll pull the hubs, take a look and report back.

As for the leak, is this a serious problem or will I be ok keeping the transfer case full of fluid?

Proverbs 1:7

 

If it's bad enough to cause a vibration there should be movement. If just a growling noise maybe no movement. If noise only, whlie driving, with no traffic around, cut the wheels back and forth (swerve) the noise will get louder and softer if it's a bearing.

 

a another thing to look at is grab the u joint and move it up and down, if it has a lot of movement the bearings is bad. if has very very litle the bearing is good.(i am only refering to the small bearing that the stub shaft rides on)

 

Never heard of pushing up and down on the U-joint to check hub bearings but there's a LOT I don't know and love learning new tricks! I'll give it a try! If that doesn't give a clear answer and since there is more growling than vibration, I'll pull'em and see what's up.

If anyone's interested, I'll take some pics and post'em for review.

 

being that the hub bearing is a whole assembly(spindle,hub bearing,hub, all in one) normally pushing the u-joint will not find bad bearings but the way these are made, the stub shaft ride on a very small needle bearing and when it fails you have free play were the shaft goes in to that little bearing. the little bearing is inside on the back of the assembly, that and the locking hub are the only thnigs supporting the stub shaft. i had my small bearing fail and it tore up my stub shaft and the locking hub. after i pulled it all aprt the internal large hub bearing seememed to sound fine. I actually drove 800 miles with the left axle shaft removed and the bearing was smooth. the big bearing is pressed into 2 pieces of an assembly and is sealed really well the little bearing is first little and only protected by the locking hub seal and the hub air seal.