Possible Rear Diff Leak on 2023 4R

Looks like I may have some kind of leak in the rear diff. Taking it in to the dealer in the morning. I'm kinda surprised I'm encountering this at only 10k Mi on my 2023. The back side where the fill plug is looks dry and normal.

 

Looks like a leaky gasket. Gonna have to pull the cover and reseal.

 

Check torque on the bolts but it’s just weeping.

 

Warranty. Seems to be more issues with post Covid 5th gens.

 

Yep, time for a dealership visit.

 

Dealer tech sent a message saying that "Per Toyota some seepage is normal, and for Toyota to consider it a leak it has to form a droplet." He said he would clean it off really well and for me to monitor it. Still under warranty so we will see how it progresses with time ¯\_(ツ)_/¯

 

Sad, it would not take them much time or effort to reseal it. Prolly cost more in gear oil is all.

 

It wasn't normal when 3rd gen Tacomas had a recall for this issue...

 

Toyota changed their policy on leaks a while ago. These are now seeps. Leaks as they said have active drips. They won't repair seeps.

I'd wash it off and monitor.

 

agreed

 

Did they re-torque the nuts on the studs? I would at least try to tighten them just a little if they didn't.

 

The good news is you won't have any rust there.

 

These don’t have covers. The driveshaft has to be unbolted and the carrier has to be removed to seal that surface. So I wouldn’t consider this a risk free warranty claim.

I bought a 2006 Sienna new, and it had a similar weep on the transmission. Even back then I must have been salty on dealers, and I just let it be. I didn’t want anybody splitting my transmission to maybe successfully seal a weep. It never got any worse until I sold it in 2021.

I see a disturbing lack of woolwax on the pics of that undercarriage however. Once it’s liberally coated and driven on some dusty gravel roads, that weep will be only a memory.

 

^Woolwax in Texas results in a gooey undercarriage with no real benefit.

I would suggest getting this in writing, ideally in the form of a Toyota tech tip or bulletin document, because previously it was pretty unequivocal in the Tacoma recall instructions filed with the NHTSA. Tell the dealer you are concerned about it being a safety issue as described in the recall, https://static.nhtsa.gov/odi/rcl/2017/RCRIT-17V285-0775.pdf



In the Tacoma recall instructions, if the tech saw seepage like yours, he is required to drain the oil into a Home Depot bucket and measure the remaining oil amount. If less than 2 liters remain, the diff is considered beyond saving and a new diff is ordered.

 

Thanks for that PDF. Good stuff!

 

As far as I am aware there was nothing done other than a visual inspection.

Haha well that is some potential good news at least!

Thanks for the bulletin! Does not inspire confidence that I'm supposedly good to drive without any other inspection. The paperwork they gave me when I picked up says what my other comment states. I also downloaded and stored the video they sent of the inspection where the tech says the same thing as the paperwork. I'll keep an eye on it for now.

I do like the idea of the HD bucket with the measurements and will pick one up for when I do my diff oil replacement. Probably do that early with my next oil change at 15k unless I see more leaking.

 

^Going by your pics, I don't think it'll result in a harmful reduction in oil level, unless the leak gets worse. When you do the diff oil replacement, since you're supposed to open the fill plug first, reach in the fill port with your pinky. Rule of thumb (pinky?) is if you can get oil on your pinky, the oil level is within service specification (fill port +/- 5mm).

 

If you suspect the oil is too low (after doing what @3JOH22A suggested with the pinky test) DO NOT change the oil yourself. At that point have the dealer do it so they can document the oil volume themselves and potentially give you a replacement per the Tacoma bulletin.

However, it looks like that won't be the case with the small amount of weeping in the photos. Just make sure it doesn't get worse.