rare front differential oil leak

[vidvis]

I thought about that Humtech, but again, there is no trace whatsoever of diff. oil getting past the shaft seal. I thoroughly hose everything down with parts cleaner before taking it out for another drive. The only traces of oil is on the perimeter of the flanges near the bolts - no sign of it running down the face of the flange or along the stub of the shaft or anything like that nor is there any trace of an oil leak anywhere on the diff. case

Yesterday I unbolted the half shaft from the output shaft again, and again found a small amount of oil in the space between the flanges as well as on the perimeter of where the flanges come together. I cleaned it all up and then applied a small amount of gasket sealer to the flange faces and bolted them back together.

I later drove about 60 miles on 3 seperate trips between city and highway and inspected for oil each time. No trace of oil anywhere whatsoever.

I have yet to unbolt the flanges and see if there is oil built up in the space I sealed.

Humtech, if I find oil in there, what would that mean? I thought the output shafts were solid. As for the half shaft, it does have an end cap pressed into it on the flange end that bolts to the output shaft, but it seems solid and I can't imagine something exactly resembling the clean gear oil I changed not that long ago coming from a half shaft.

[vidvis]

Humtech, I forgot to add, there is no bolt on my drivers side output shaft (or passenger either). Once the halfshaft is out of the way on the DS, the output shaft can just be tapped out. Is my output shaft different from what you have seen before???

[HUMTECH]

My bad, I was thinking about an h-1 diff where there is A nut holding the stub axle in. I will have A look at one tomorrow if I get A chance to try and figure out where that oil can be coming from.

[vidvis]

Thanks for the info. Humtech. Yesterday I separated the half shaft flange from the output shaft flange that I had previously reassembled with gasket sealer in addition to the bolts of course. I drove it around plenty after having let the sealer set up. When I opened it up, I found a small amount of what appeared to be gear oil inside the sealed area. However, I don't think it is was gear oil at this point.

The flange of the half shaft has a lid or cap pressed into it. I presume that make it easier to access if someone wants to rebuild it later. The oil appeared to be leaking from an area where the cap is pressed in. I am guessing that grease inside the CV joint area of the half shaft gets a bit runny when warm. I always thought the lube inside a CV joint would be a heavy grease that doesn't get that liquidity. By the way, the CV joint never got to feeling any warmer than the other one, and it is not making unusual noises or have any abnormal play in it either.

I cleaned everything back up, and again used gasket sealer prior to assembling it all and have no more leaking issues.

Would you replaced the half shaft or just leave things as is? Is was a replacement product from Napa, is about a year old, and only has 6k-8k miles on it.

[IRA51]

That is why I said to make sure both the diff fluid and your leak was the same ,glad you found it .

[vidvis]

Ira - you were right. Geez, I've been working on my own vehicles for 30 years and even when I go back and compare the two substances, it is still hard to tell the two fluids apart. If not for seeing the oil/liquified grease seep out from the halfshaft end cap, I would still be looking for the cause.

The halfshaft was still under warranty and has already been returned and replaced with a new one.

[IRA51]

The way I check the diff is to put a bit on a paper towel of each and look at the color and see how it spread and than smell them both ,most of the time you can see right away if they are the same . you don't expect a new part to be defective.