Please Help, Front Differential leaking BAD

[Shane91Explorer]

My brother just bought a 2000 Ex with the 5.0 and AWD. It had a bad front differential when he bought it. We thought it was a bad bearing when he test drove it, but it turned out the diff was leaking. It only leaked at high speed and out of the driver side seal. So we got a used one at the wrecking yard and spent 4 hours putting it in on Saturday. The thing sounded beautiful, went down the rode perfect.

He called me last night and said this new one is leaking from the same place, like a civ. It started after he did some extensive freeway driving again. Has anyone experienced this before? Is it something to do with the vent tube possibly? Apparently there were some vent tube issues with these front differentials.

The only thing in common with that side is I did not change the CV axles. I did the swap without removing the driver side CV axle, So I didn't really inspect it all too well. Hindsight is always 20/20 though.

Any comments or suggestions are greatly appreciated.

Thanks!

 

[Cobraguy]

Did you check the axle seal surface to see if there was a groove worn in it? If so, all the seals in the world won't seal it up.

 

[Shane91Explorer]

I didn't look

Thanks for the post! I assumed it was OK. I didn't pull that shaft, I left it in when we did it and I didn't inspect it at all. When we pulled the old axle I noticed it had a chunk missing from the lip on the seal, so I thought that was the issue. Apparently there was an underlying cause. I am going to pull that side and check it out.

I have been told by 2 mechanics as their first diagnosis that it's probably the one way valve on the breather tube. Apparently the fact that it only leaks under high speed is an indication of that.

 

[Cobraguy]

If there is a groove in the axle, see if there is a "problem solver" seal available for it. That us a seal that moves the sealing surface to a new portion of the axle.

Good idea by your buddies. If the vent is plugged, it can cause leaks past the weakest link.