I have a 2004 FX4. I have replaced the RR axle seal 2x and I’m still getting leaks. The bearing is new also, so I was wondering , if the bearing is not back all the way or at an angle ( no noise from the bearing) , would that cause the seal to fail?

 

How did the two seals that you removed look? Were they damaged? You can tell by looking at the sealing edge. Might be that you have a burr on your axle and you're cutting the seal when you insert the axle.

Might be that the leak is not at the seal surface but at the seal mounting area. You can use a gasket maker to seal that area when you press the new seal in.

Could also be that the axle is damaged where the seal rides.

Get a magnifying glass and a bright light.

 

I did check for burrs, I took a look at it today and it looks like the axle no longer is big enough to fit in the oem seal. The fluid is leaking out of the rubber axle mating surface with the axle shaft. Maybe prior owner did something?both seals seem to fit just fine which is what is puzzling. New axle? I kinda don’t know what to do

 

I don't know a lot about Ford axles but Rockauto shows two different journal diameters for the 9.75 inch diff. Wouldn't be a surprise if the outer diameter of the seal in to the housing was the same for each, with different ID's.. Check your part numbers, maybe you a got a big one but need a small one.

It's odd that the 8.8 has bigger journals but that's what they show. Browse down toward the bottom. I found it in axles but didn't find the corresponding seal. It might be there. They're under the Brake and Wheel hub section.

https://www.rockauto.com/en/catalog/...le+shaft,10439

 

Here's the seals. Quite a variety to choose from, looks like you have to know some tag numbers or model specifics.

https://www.rockauto.com/en/catalog/...heel+seal,1860

 

Thank you sir, much appreciated