Rear diff fluid change needed?

Believe it or not, but I've been through deeper with my Honda CRV!

With the CRV, when you hear a squealing when turning, it was time to replace the oil. No damage, no problem. Keep on trucking!

 

If you are asking yourself to change it more than likely u need to change it .

 

Negative.

 

I've never understood the rear diff vs. water vs. diff breather talk. How many people with Tacomas pull boats in and out of the water dozens of times a year without issue? Literally thousands, if not 10's of thousands. I suspect if it was ever a common problem, Toyota would have made some sort of change. You never hear about rear diffs grenading, unless there's shenanigans involved like spinning a tire on ice straight to dry pavement (because physics). I've dug deep into this before, and there's less than a handful of instances of water in the rear diffs (for any reason or circumstance) since Tacoma World has been around. I understand the theory of worn seals, the temperature differential, and all of that, but have yet to see anything that actually supports any of it as being true. Not saying it can't happen, but it's certainly nothing to worry about IMO.

I think the diff breather mod is fine for newcomers to feel good about doing something proactive to their truck. Hell, I did the A/C drain mod right when I got mine, which I'm sure 99.9% of owners would never bother with. Both are cheap and harmless, but questionable at best if they actually help anything.

Maybe when my truck has 500k miles and I finally decide to retire it, I'll take a blow torch to my rear diff before I back it into a frozen lake and leave it there for a day, and then we'll see what's what.

 

No water, as expected. Pulled the fill plug and took a look.