rear differential leak

[poundkey]

Hey y'all,

The problem: The rear differential on my 2016 4Runner is leaking.

The question: How do you recommend fixing this?

The details: My 2016 4Runner SR5 4WD has about 48,000 miles on it. I just noticed this morning that the rear differential is leaking oil onto my garage floor at the rate of about one drop per hour. Upon removing the fill plug, I noticed that the fluid level is just below the hole, which makes me think that the leak just started.

After cleaning all the dirt off the differential/axle housing, I noticed that the front is speckled with rust. I live in Southern California, away from the beach, so I think that road debris has chipped the paint enough to allow rust to start. It's not much rust yet, though. The back of the differential/axle housing is completely free of rust.

The source of the leak is the weld around the drain plug "collar" (see the photo). When I wipe it clean, I can see oil starting to seep from the weld after about one minute. The drain plug is tight, and no oil is leaking from there.

Since it's leaking somewhat quickly, yet still almost full, I suspect that the drain plug "collar" was hit by something recently, but there doesn't seem to be any sign of major impact. Only some scrapes in the dirt/mud suggest that I might have hit something that is not coming to mind.

What would y'all do in my case? Is this something that should be welded? Or would JB Weld (after sufficient grinding of paint for proper adhesion) suffice? Or stick bubble gum on it and get back to washing the bugs off the front of the vehicle?

Thanks!

 

[M22]

Warranty repair

 

[S54MCoupe]

JB Weld

 

[coltm4]

Warranty. Poor quality welding.

 

[Jeremy556]

Looks like you are maybe missing 1/4 of the bung around the drain bolt, but hard to tell with all that crap. Hose it down with brake cleaner to see what we are working with, please.

 

[poundkey]

I did some more searching and found someone else who had this exact problem on a 2012 4Runner. He said that the housing was replaced under warranty. As much as I want to avoid taking my vehicle in to have work done on it, I think it's the best route.

I'll plan to post an update when everything has been resolved.

 

[poundkey]

Follow up:

I took my 4Runner in to the dealership (Longo Toyota in Los Angeles), and they agreed that it was a faulty weld. The entire rear axle housing was replaced under warranty. Since a 4Runner rear axle housing isn't something that is kept in stock, they told me that it could take a few weeks to resolve (as I drove away in my sad little dealership-provided rental car). However, they were able to complete the work by the next afternoon! A thorough post-work inspection showed that everything was bolted back correctly. It's kinda weird seeing a clean part on the vehicle!

Anyway, this is my third 4Runner; I put 200,000 miles on a 1997 and 300,000 miles on a 2002. This is the first time I've had any kind of "premature" problem with Toyota, and it was nice to see that warranty work was performed quickly and easily.

So, as much as I wanted to smear some JB Weld over the crack in the weld and call it done, I'm glad that I got it repaired correctly - and before the oil level got dangerously low! All it cost me was some time driving on Los Angeles freeways.