My local Toyota dealer is replacing my front differential under warranty this week. Wondering if anyone has had this issue and if there's anything else I might want to keep an eye out for?

It's on my 2015 4R SR5-Premium, 19,000 miles. I started having a throbbing, grinding, rubbing sort of sound, a few months ago (not loud). It's most pronounced at about 30 mph coasting down a slight incline. It's taken months to diagnose and many trips to the shop, which is a little frustrating but I feel like they've done what they thought was correct and have good customer service, so I'm satisfied with their service.

The first trip they bent back some heat shields and that seemed to improve it, but I noticed it wasn't gone. Then the next time they replaced a pinion bearing in the differential. That also improved it for a short time, but it "came back." Now, after working with Toyota, they're going to replace the entire differential.

I'm happy to have found it while still under warranty. The odd thing is, ever since I bought it 15 months ago, I've suspected something wasn't quite right because from the day I took it home I never got more than 17.5 mpg and the car I replaced, a 2006 4Runner, got 19-19.5 mpg with the exact same driving patterns. I'm hopeful when I get it back I see a mileage improvement.

I realized I actually posted about my paranoia over the MPGs I was seeing Dec-14.

This may be a classic self-fulfilling prophecy or I KNEW IT!

MPG Paranoia

It will be interesting to see if you notice any change in mileage after the repair. Don't be surprised if it actually stays the same or goes down a bit this differential is brand-new and tight for a bit. But it probably won't matter. It's very unusual to have a failure on one of those. I hope it all goes smooth it works out to your satisfaction. Keep us posted .

Based on the threads here, it doesn't sound like a very common problem. I think there was only one other thread a few years ago where someone else had to have their front diff replaced. Hopefully it resolves your issue.

FWIW, my 5th gen has never been able to get as good of mileage as my 4th gen.

i just got a 2016 and I have noticed the same problem

We just replaced a front diff on a 13 fj with 11k on the clock

Mine makes a little bit of noise when it's cold out but goes away after a few min when it gets warm so I'm not worried about it

17.5 MPG is close to max for the Gen 5. Don't believe there have been a lot of recent diff failures.

Any update on this? I think I have the same condition. With start of colder weather, I'm starting to hear mine again. Hadn't heard it since last winter. Mine is 2016 Trail w/ 30k.

I have noise when coasting as well. I changed rear diff oil recently and the noise is a tad less, but now I'm paranoid the front may have issues. I wouldn't think the front diff would make a noise that differs when under power or coasting since i have a manual transfer case and I'm not in 4wd.

This sounds like it could be a needle bearing issue. It's a relatively common problem, usually more prevalent after a lift. Run a google search and you'll come up with plenty of info. You can test for it by engaging 4wd whenever you feel the vibe. East Coast Gear makes a bushing replacement that people have had success with.

Actually yeah. The FJ was a one off but there is a TSB for the needle bearing in the front diff that makes noise. I had the job done on my Runner and the noise went away. I will try to find the TSB for you guys

Edit: Here is it. If the link does not work it is T-SB-0026-15

https://one.tis.toyota.com/t3Portal/...-T&context=int

I'm at 16.9 MPG from day one. then again I'm in the worst traffic in the country.

it's actually a very common problem effecting all vehicles on the platform

the less common part is getting toyota to fix it by replacing the diff (which is still a bandaid because the design is still the same)

i had noise when i bought mine but it went away, if it ever comes back i'm going to install the east coast gear bushing

FYI, I'm pretty sure my noise is/was being caused by the splash guard(s) as referenced here Squeaking noise solved on my 2011 Trail Edition and here dreaded dash rattle - omg going insane

I had the same groaning I have a 2017 with 26k on the clock. only happened when it got cold out (like 43 degrees or below) I took it to Toyota last week and they said they will replace the front diff. they didn't fight me on it or anything, which was good I guess.

I dropped it off this morning and they said about two days. So we will see.