What is this problem?

Got a 2014 Toyota Sienna minivan with about 130k miles. What is this leak in the picture?

That’s an odd viewing angle/perspective but it looks like the RF inner CV boot is slinging grease around. Is that residue kind of thick and greasy?

From the image it’s hard to tell, but it might be a transfer case leak.

Here’s the transfer case.


Hope it’s a torn/cracked CV joint boot on that axle, either jack up the car, put it on a jack stand, and inspect it or take to a shop and have them inspect it.

Thanks. That is a quick shot from underneath the car. It was hot so I didnt touch it, too much. It follows the transfer case joint. Assuming there is a gasket. Is that an expensive fix and is it something I could do?

It does follow the joint, but to the right it’s also along the rest of the area, that pipe, that hose, etc. So it might just be coincidence that it’s along the joint. An inspection of the boot will answer that quickly. The reason I’m hoping it’s the boot is that replacing that axle is much cheaper. Either repair should be done by a shop, given your questions.

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The inner CV boot is leaking from the clamped end. The rubber shrinks with age and the boot becomes loose. Tighten the clamp with a CV boot clamp pliers or replace the boot.



Ok appreciate it. For reference, what are the two metal pipes on the right? Ac low and high pressure? And what is the black hose?

Just to get my orientation - is that the passenger side axle?

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Those are the low and high pressure refrigerant lines to the rear A/C unit.

Yes. And the grease is being flung onto the timing cover area of the engine. There’s no way that could be a transfer case leak. Judging by the picture I don’t the car is AWD.

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Yes that’s correct. It is 2wd. Passenger side view.

Agreed, that is the typical right side Toyota/Lexus axle shaft with the center support bearing that likes to seize up in the bracket, if the bearing doesn’t want to come out of the bracket I just cut the jackshaft (intermediate shaft) in half (new axle comes with the jackshaft and bearing) and press it out, but I have had to even replace the bearing bracket in a few cases, dealer always had plenty of the brackets in stock…

Here is a better picture. Could it be the other bootin the picture that is ripped? The smaller one? I assume the bigger boot houses the cv joint? I felt around and could not find any tears and both booths feel similar to the other side. Again, picture is passenger side.

The small one is your rack-n-pinion bellow boot, it keeps the water, dirt and butterfly’s out of the inner tie rod end and end of the rack, if it is leaking then you will be leaking power steering fluid from the rack-n-pinion end seals… The thick greasy nasty stuff being slung out in a circular pattern is coming from your inner CV Joint of the Axle assembly…

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Thank you for helping on this!

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Like another poster said, the boot’s clamp is loose, not torn. New one on me.

The CV joint rotates, the rack and pinion linkage doesn’t, so any grease being slung around in a circular pattern like that has to be coming from the CV joint. I’ve had CV boots split and fling grease, but never had a clamp come loose. I replaced the CV boot clamps on my Corolla with worm drive hose clamps, seems to work ok for me anyway. The advantage is, no special tools required. Doing that could cause a shaft-imbalance problem possibly though.

Suggest to inspect the boot again. Still possible you have a split in the boot. Clean it with soap and water first, then carefully inspect all the pleats. If you have a split in the boot, the boot must be replaced asap.