Front axle leak-fix or? (pics)

[slowride]

Bought this '04 Tahoe sight unseen at an auction, drove it home and went to do an oil change and found this leak on the pass side of the front axle. Looks like its been like this for a while. Most of my other ones have been 2wd so havent run into this before. Does this need a new seal or something immediately or is this common and not critical? Thanks

 

[OR VietVet]

If it is slinging fluid, like it obviously is, then the axle could be low and since you just bought I would change the axle fluid and if you have not done the seal replacement before, watch a you tube to see if you can do it. I don't see a tear on the inner cv boot, unless there is one I cannot see, so likely just the seal replacement. If the boot is torn or cracked open I would just replace the axle shaft assembly. If you just let this go you are asking for problems. Hell, it's your money not mine, do the rear axle fluid change and do the transfer case fluid and do the trans filter and gasket at least. What is the mileage?

 

[slowride]

180k, the rubber boot is good, looked to me to be seeping from between the two flanges that are bolted together but Im not sure

 

[OR VietVet]

It is leaking where the axle shaft slides in at the seal. When you pull it apart make sure to check for any grooves where the seal rides on that shaft. New seal and old shaft with grooves means it will leak again.

 

[Summajet]

It is the seal. I did both seals on the front axle. Anaerobic sealer when reassembling. There are no gaskets, just the sealer. It is not a hard job. Take time and take pictures before you disassemble the yoke assembly on the passengers side. Take pictures of the bolt/nut orientation.
1A auto has a good video on their site.

 

[OR VietVet]

By the way, clean the surrounding area so that when you do the seal replacement and if it still leaks you can see it. Plus, if you want to take care of your rig you should always clean up any area after a repair.

 

[SnowDrifter]

Looks like the output shaft seal. Pretty common leak, and frankly, easy. Can use a socket and extension to press them in and out. Just measure the depth before you start fussing with it as there's no shoulder to seat said gasket against.

Barring that... It's a pretty straight forward job. Literally, start pulling bolts off and it'll become obvious how it's done. Just put everything back together in the same order you removed it. There's a "pack" of stuff that comes off for the 4wd engagement.

 

[Summajet]

Output shaft seals. Here is the youtube links I used to aid in the repair,

There is a second video shows final repair.

 

[CTUBS8732]

Nice. I have my front diff off. Im going to do this asap!

 

[West 1]

The seal leak is very common on the GM front differentials. The driver side is much easier to replace than the passenger side. Behind the seal on both sides is a small roller bearing. If the bearing is worn it can allow extra movement in the shaft and cause short seal life.
There is also a vent on the front differential. If the vent is plugged the seals will start leaking every time you take a long drive due to pressure build up inside the differential.

CT, since your diff is removed it is pretty easy to replace the seals and bearings while out to avoid future issues.

 

[CTUBS8732]

The weird thing is it's not wet where the shaft and diff meet, it's wet in between where the cv and shaft bolt together on both driver and passenger side.

 

[West 1]

There is no oil in the shaft so either you have a leak above the CV shaft dripping down on it or it is coming from the front differential seal.