Source of this leak?
 

Hoping someone here can help diagnose. Vehicle is a 2010 LS460L AWD.

Noticed a few drops of oil (or something) on my garage floor so I jacked up the car and went crawling around to find the source of the leak. It looks to me like it's the driver's side front cv axle seal (#3 in diagram below) as the spray pattern indicates the leak is being flung off the axle. And if that's the case, the leak I'm seeing is trans fluid.

Are there any other seals located near or above this area that would cause this?



https://parts.iralexusofmanchester.c...ze/F88C060.png

Looks like CV joint may be giving up the grease from a seal.

The grease in the axle boot you mean? Seems like a lot of fluid to be that, and I would imagine it wouldn't be this runny. However, I guess water and crap on the road could have mixed with it to thin it down.....

EDIT: Now that I'm looking closer at the second pick, does that look like a tear in the boot? Car is approaching 100K and I assume that's the factory axle so a torn boot is entirely possible.

That's a strange leak, right away I thought a torn axle boot but you're right, it doesn't look like axle grease...it's too much like a liquid. And your picture shows the fluid coming from above where the axle comes out of the diff. And then it looks like it's getting thrown around by the axle. Is it oil? Are you losing oil? Check the level to be sure.

I guess it could be axle grease mixed with water but it doesn't look like it to me. And it doesn't look like differential or tranny fluid either. Whatever it is it looks like water has mixed with it and it looks like it's coming from above the axle.

Strange indeed. In the third pic it does look like it's dripping down from above the axle and making it's way to the seal/axle from there. BUT, that's completely dry, like it was from a very old leak. In fact, everything you can see in those pics that's above the axle was dry.

Engine oil level is fine, don't even need to top off between 8K OCIs.

I'm thinking I may need to pull everything apart on the front drivers side to get a better look at it. If I can't find a source then, I'll take Simple Green and clean everything up as best as possible and keep an eye on it to see where it starts from.

Do our transmissions have a dipstick or are they completely sealed?

Sealed. Take it to your Toyota dealer and have them change out the fluid. While they're in there, they can tell you where the leak is coming from. My guess: transfer case.

Getting it into the dealer for a trans, brake, and diff fluid changes have been on my list of things to get done. I guess this forces me to stop procrastinating.

UPDATE: I decided to rotate the tires last night so that I could inspect everything a little better and was able to nail down that, yes, it is leaking from the cv axle seals in the transfer case. And yes, you read that right, "seals" plural. Here's the seal on the passenger side...

https://cimg6.ibsrv.net/gimg/www.clu...f8a77448ad.jpg

While not as bad as the driver's side, it's still leaking the same horribly colored fluid from both sides of the transfer case.

Question: I know I can replace the seals myself and likely save a ton on labor over what the dealer would charge due to suspension disassembly, but I want them to do the fill according to procedure. What are your thoughts me performing this work and then having it flatbedded to the dealer for the fluid drain and fills? Is it worthwhile to let them do the replacement so they can inspect for any possible issues that may have caused them both to fail? Anybody know what to expect for quotes?


Also, I was able to determine where the dried discoloration above the axle seal on the driver's side came from. There's a relief valve of some sort located on top of the transfer case. Does anyone know the function of this and what conditions cause it to release? Unless, of course, that's not a relief valve and is something else entirely :P

https://cimg1.ibsrv.net/gimg/www.clu...bb93f4fa63.jpg

Thanks for any and all help!

Great Pictures. My Goodness, good luck Man. Some of the guys here will have some good pointers. They always do.

Thanks, you should have seen some of the contortions I had to get into with flashlight in one hand and phone in the other to snap those :D

I've been using forums to DIY for as long as I can remember so I try to contribute as best I can where I can. Getting good photos that others can reference to see if they're dealing with a similar issue is key.

That does look like a release valve, similar to what you'd see on a rear differential. If it's clogged it could cause the fluid to push out of your seals (makes sense because both of them are leaking). Try cleaning it off.

I'd clean it off, then I'd check the fluid level and add as necessary. Then I'd clean off the entire differential housing and recheck it in a week. If it's clean then it was the valve and it didn't permanently damage the axle seals.

That sounds like a safe bet to at least see what I'm dealing with. Will likely do that when I get home this evening and will update the thread in a week or so with results.

Does anybody know more info about that relief valve? Does it only open if something is wrong with the trans or is it a "every time you drive a little pressure escapes" type of thing?

Okay guys, found something concerning last night while I was cleaning everything up...


Play in the inner CV axle is expected, but would you consider this excessive? There are absolutely no signs (sounds, clunking, steering wheel feedback, etc.) which would lead me to believe it's bad other than grabbing it with my hand and moving it.

Circling back to this, the "valve" is simply a passthrough fitting with a spring loaded cap. Wasn't clogged so couldn't be the cause of the leaking axle seals.

I have never seen a CV move that much before. I am by no means an expert but it seems excessive.

Me neither, but this is also my first AWD vehicle equipped with an air suspension that has a TON of travel. But if it were broken I imagine that I'd see/feel/hear some signs of it while the car is in motion, correct?