Weird leak?

As the title states, I have this weird leak around the rear passenger wheel.

I'm going to take it to the dealership soon but has anyone had anything like this happen? My entire wheel is coated in grease/oily substance and it coming out the front of the center cap of the wheel.

 

Brake fluid ?

 

If it's brake fluid, you'll know soon enough, when it starts eating your paint.

 

Axle seal?

 

Smell it. If it reeks, axle seal. If not, brake fluid.
Head to the dealership.
How many miles?

 

By the smell test, it's axle seal, truck has 19,000 miles on it.

 

Possible axle seal blow, consider washing the truck off first so they don't try to blame the offroading.

 

Damn. Any chance the vent is plugged?
I’m at 21k. One more thing to watch for...

 

I don't think so, I have an appointment scheduled this week for them to look at it, I'll update when I find out what it is for sure.

 

I'd take the wheel off and look for the source before I'd fuck with the dealer.

Any axle seal or brake cylinder leak will be mostly contained inside the drum. It will eventually get flung out between the drum and backing plate and coat the inside of the wheel. There is no direct patch for it to go into the center cap.

How long have you had those wheels on before this leak started?

 

The wheels have been on the truck since 0 miles. The dealer put them on before I picked it up.

I also had them on my 17 for ~40k or so miles with no issues.

 

Turns out it was my rear axle seal.

The dealer is replacing the seal, wheel bearing, and brakes, I'm not too sure how it failed but it was warrantied, so that's a plus.

 

No, the toughest thing this truck has seen is groomed gravel roads with occasional pot holes.

 

I've read of this happening with previous generations. When I did my diff breather relocate a lot of pressurized air came out when I took off the stock breather, the diff was even cool after sitting overnight.

It was the reason I did the all open breather relocate not because of water crossings, but after reading this. Also, it's my theory why the rear diffs start to "seap" fluid around the bolts.

 

When I replaced my dif oil, the truck was cold and sitting overnight. Took the fill plug out and a woosh of pressure came out. Checked the breather and it was surely stuck. Truck had about 11K on it and was never off the pavement. Took the breather off and shook it like a PCV and no noise (there should be). Stuck a small allen wrench in the end and felt a pop. Sprayed a tiny bit of silicone lube in there and shook it around and let it drain on a paper towel. I've checked it twice in the last 11K (Truck now has 22K) and it's still free. I will eventually do the breather mod like I did to my 3rd Gen 4Runner. Oh and in case anyone's wondering why I changed my dif oil at 11K, I put in the Redline HD SHockproof gear lube to see if would quiet down the noise I have back there when I let OFF the gas between 52 to 62 MPH. No real difference.

PS Just Read Grossmotto's experience which seems identical to mine

 

I don't think they're supposed to make noise. There's just a spring and flap/seat under there. The seat is always under spring Compression until it needs to burp air out.

 

I shook it really hard. It's a very light spring.

 

Yeah you're right. That spring did look anemic. Someone tore one open on here and it looked thin.

 

Pic of disassembled breather in the below post for those interested.

https://www.tacomaworld.com/threads/rear-diff-breather.431400/page-4#post-23799846

 

Thanks. It's way too early for me to look that up haha